Is Al-Qaida opening a Gaza front to counter Hamas?

Explosions at two sensitive sites in the Gaza Strip over the weekend prompted speculation on Sunday that they were the work of Al-Qaida-aligned radicals opposed to the Palestinian enclave's Islamist rulers Hamas.

No credible claim of responsibility has been made.

Since Hamas seized control of the Gaza Strip in June 2007 by routing secular forces loyal to Palestinian President Mahmoud Abbas, the Islamists have tended to blame occasional bombings and other attacks on Hamas targets on Abbas's Fatah party.

This time, however, suspicion has fallen on fundamentalist Muslims, or Salafis, whose agenda of global jihad, or holy war, against the West is at odds with Hamas's nationalist goals.

Hamas forces attacked a mosque in Rafah on August 14 after the leader of a group calling itself Jund Ansar Allah (Warriors of God) declared Islamic rule in the town on the border with Egypt.

Up to 28 people, including the leader, were killed. That spurred warnings of a reaction and speculation that conflict with Salafis could both complicate and foster Hamas's contact with the West.

The fighting was sparked by a rebellious sermon by the group's leader, and his dramatic death put an end to the greatest internal challenge to Hamas' rule since it took control of Gaza two years ago. It was the highest death toll in the territory since the Israel-Hamas war earlier this year.

Most Salafis share an agenda with Al-Qaida and believe Hamas broke with Islam by taking part in the 2006 Palestinian parliamentary election - an election which it won, sparking international sanctions. Since Hamas seized control of Gaza in 2007 from secular President Abbas, Salafis have criticised the Islamist movement for failing to implement Islamic law.

Though they may not have a clear hierarchical connection to Al-Qaida, they admire its leaders, Osama bin Laden and Ayman al-Zawahiri. Reliable data is scant but various groups may gather hundreds of fighters, including some trained and blooded in the ranks of Hamas but now disillusioned with the ruling movement.

The attackers hit two heavily guarded Hamas security compounds, one known to include a prison. The second, a residence of President Abbas, is also believed to be used now for detentions and interrogations. If Salafis were behind the bombing, they may be showing both their capabilities and a demand for dozens of imprisoned radicals to be freed.

Hamas has thousands of men under arms and easily outnumbers any other radical groups in the coastal territory. Nonetheless, radical ideology and an ability to blend into the population make the Salafis a difficult opponent when they avoid direct confrontation.

Another degree of irritation for Hamas is the Salafis' ability to attack Israel, provoking an Israeli reaction at times when Hamas may be trying to observe a truce.

Hamas officials say they are concentrating on "re-educating" captured radicals, hoping to win them over to a brand of political Islam more in line with Hamas's own principles.