An unusual announcement was posted this week on one of the Islamic sites on the Internet. Al-Qalaa, which usually serves as a message board for Al-Qaida, informed its readers that "several hours after the bombings in London, someone posted a notice in the name of an unknown organization claiming responsibility for the attacks. Although we have requested many times not to post such messages on our site, this person did so anyway." Soon after, the whole site was pulled from the Web by the service provider. Now Al-Qalaa is operating from a different address.

Such announcements are unusual on radical Islamic Web sites. Most are busy competing among themselves over the latest Al-Qaida scoop. They even provide their readers with alternative addresses in the event the "Western intelligence agencies close us down."

The question is why an organization, whether or not it is responsible for the attack, would post the news on a site that clearly discourages such postings. The answer may lie in the battle for control of cyberspace being waged by dozens, if not hundreds, of radical organizations. A site like Al-Qalaa that is radical, but not radical "enough," stands a good chance of being targeted by an even more radical underground, which will plant the kind of message that will cause the site to be shut down.

On one Islamic site, the site manager openly admitted that other Islamic organizations were a greater cause for worry than the CIA. "The Americans," he wrote, "are actually interested in what we have to say, but these organizations are fighting us, just as the Arab governments are, because we give their opponents a forum."

This rivalry between Internet sites apparently reflects the rivalry between an assortment of terror organizations the West tends to associate with Al-Qaida, but without solid proof. A day after the attacks in London, for example, an organization called Hafs al-Masri claimed responsibility. Abu Hafs is the alias of Mohammed Atef, an Al-Qaida operative who spent 1992-93 in Somalia planning attacks on American and UN bases there, and then went to Khartoum to report to Osama bin Laden, who was living in Sudan at the time.

Atef was born in the city of Minya in southern Egypt; he began his career as a terrorist by conspiring to take over the local police force. Atef managed to steal a few guns from watchmen at the local Coptic church and security guards around the city, then he moved to Cairo and hooked up with other Islamic extremists he met there. Captured by the Egyptian security forces, he was tried and sent to jail for five years. Upon his release, he went to Libya and from there to Saudi Arabia, finally ending up in Afghanistan. He married a Pakistani woman and joined forces with bin Laden, who appointed him "chief of operations" after Abu Ubaidah al-Banshiri, the former chief, was killed. With Atef's help, bin Laden established another branch of operations in Nairobi, Kenya in 1993, with two shell companies - Asamaa and Tanzanite King - serving as a front for terrorist activities.

Hafs al-Masri returned to the headlines during the war in Iraq. In the summer of 2003, it claimed responsibility for the attack on the Al-Qanat Hotel in Baghdad, which was being used as a base for UN relief operations. This organization also took responsibility for the bombing of synagogues in Istanbul, as it appears to do every time some major attack takes place, no matter where. In this way, it has built up a connection to Al-Qaida, but without any findings that prove the link between them. Later it was discovered that the synagogue attacks were the work of Turkish terrorists, members of a local organization who fled to Syria and were eventually extradited to Turkey.

Also suspected of involvement in the London bombings is a ring operated by Abu Musab al-Zarqawi, leader of what is believed to be the Iraqi branch of Al-Qaida. According to a series of unconfirmed reports in the British media, the London attacks were an "Iraqi export," making use of Muslims with British citizenship. At the moment, though, there is no solid evidence linking these attacks to Ahmed Fadl Nazal Khalayla, also known as Abu Musab al-Zarqawi or Abu Taysir. Before the war in Iraq, al-Zarqawi was portrayed by U.S. Secretary of State Colin Powell as the liaison man between Saddam Hussein and Al-Qaida. Powell was relying at the time on evidence that Al-Zarqawi had been treated at a hospital in Baghdad after losing a leg in the U.S. invasion of Afghanistan.

Before that, al-Zarqawi's name surfaced as the Jordanians were investigating the assassination of Lawrence Foley, an American diplomat, who was shot to death in Jordan in October 2002. Two suspects, a Libyan by the name of Salem Saad bin Suweid, and a Jordanian by the name of Yasser Fathi Ibrahim, who had been paid $18,000 for the hit, admitted to their connection with Al-Zarqawi. Further evidence of his involvement in the murder of the diplomat was a cell phone conversation between one of Al-Zarqawi's assistants and the assassins very close in time to the murder. The Turks arrested the assistant and handed over the information to Jordan and the United States.

Al-Zarqawi, 40, is married to a Palestinian woman. He is suspected of overseeing Al-Qaida's fundraising and financing activities in the Persian Gulf, Yemen and Jordan. In 1995, he founded Bayat al-Imam (Allegiance to the Imam), a small organization of Islamic radicals in Zarka, Jordan. That year, he was arrested by the Jordanian authorities and sentenced to 15 years in jail. In 1999, however, he received a royal pardon and left Jordan for Afghanistan. Toward the end of 2000, he reached northern Iraq, where several groups of religious fundamentalists were already operating. One was the Kurdish Hamas, which had clashed with the Taliban and set up shop in Khormal. The leader was Omar Barziani, who was trained in Afghanistan. In 2001, Hamas merged with another Islamic movement, Tawhid. When Saddam Hussein's regime fell, Zarqawi established the largest terrorist ring in Iraq, although nothing is known about attacks staged outside the country.

Now, after the attack in London, another name has hit the news - Abu Musab al-Suri, whose real name is Mustafa Sit-Mariam Nassar. Nassar, 46, was born in Aleppo. A redhead with green eyes, he is married to a Spanish woman and has dual citizenship. He adopted his alias in the 1990s after writing a book about the Islamic Brotherhood in Syria, of which he was a member, calling for action against the oppressive regime of Assad (the father). The Spanish authorities suspect that Nassar was behind the train bombings in Spain last March. Since then, he has been hiding out in Pakistan or Afghanistan. But here again, the link to Al-Qaida is not definite.

The finger is now being pointed at Nassar because he was living in London with his wife and two children in 1995, at which time he appears to have been in contact with Al-Qaida operatives in Britain. According to records seized by U.S. intelligence, he provided financial backing for an organization called the Armed Islamic Militants and ran their newspaper, Al-Ansar. There is also evidence that he was in contact with Khalid Fawaz, a known Al-Qaida activist in Britain. In practice, there is no proof that Nassar, who is on the CIA's wanted list and has a $5 million price tag on his head, has been in Spain since 1995. On the other hand, the authorities know that Nassar is a wealthy man who made his money through commerce between the Middle East and Europe, and has donated large sums to Islamic organizations.

The troubling question for anti-terror organizations in Europe and the United States is whether the current attacks have been coordinated by Osama bin Laden or his associates, which has been the assumption until now, or whether they are the acts of splinter groups that have broken away from centralized control. One of the problems in cracking this case is related to timing. Two attacks - the bombings in London and the assassination of the Egyptian ambassador, Ihab al-Sharif, were carried out on the same day. The terrorist logic whereby every attack should set off the loudest possible shock waves in the media was not applied here: The murder of the Egyptian ambassador was almost drowned out by the attacks in London. If there had been coordination between the organizations, the killing of the ambassador might have been postponed. Hence the doubt about whether every major attack in Iraq can be attributed to Abu Musab al-Zarqawi.

Because they have not been able to confirm the existence of a "central command" that plans and carries out attacks, and attacks around the world are being attributed to specific terror groups that give themselves exotic names but cannot be tracked down, intelligence agencies have begun to argue about the most effective way to fight terror. Large-scale military operations such as those in Afghanistan and Iraq have not succeeded in wiping out terror. The same is true for mass arrests that yield no immediate intelligence data. Detainees have been sitting in Guantanamo Bay for four years, most of them useless for intelligence purposes, and little has been gained in the fight against terror by holding people prisoner in Iraqi jails. All we can do for the time being is continue to guess whether there is any connection between virtual postings and real life terrorists.