A Palestinian man was killed and five others wounded in violent clashes that erupted Thursday afternoon between militants and Israel Defense Forces troops at the Karni Crossing from the Gaza Strip to Israel.

The IDF said that hundreds of people had gathered at the crossing, some carrying light weapons and anti-tank missiles. Militants opened fire and hurled rocks at IDF troops stationed nearby. The soldiers returned the fire, leading to the Palestinian casualties.

Also on Thursday, IDF troops operating in the Gaza Strip found a cache of weapons. including anti-tank missiles, hidden in a schoolyard in the Sajayeh refugee camp.

Earlier Thursday, a Palestinian bomber blew up an explosives-laden truck on the Palestinian side of the Erez crossing on the Israel-Gaza Strip border early Thursday morning. The driver was the only casualty in the attempted attack.

A spokesman for Islamic Jihad said his group carried out the attempted attack in cooperation with the Al-Aqsa Martyrs' Brigades, an offshoot of Palestinian President Mahmoud Abbas's more secular Fatah faction. Jihad described it as a successful martyrdom operation.

Several hours later, Israel Defense Forces troops opened fire into a crowd of protesters at another border passage, killing a 22-year-old man and wounding 16, including three children, a Gaza health official said. The military said it was looking into the report.

No IDF soldiers were hurt in the attempted attack on the Erez crossing. The explosion shattered windows in Netiv Ha'asara, an Israeli community near the border.

The truck may have exploded on the Palestinian side due to a technical failure. As it approached the border, other militants fired mortar shells at the crossing. The explosion ripped a hole in a pedestrian passageway leading out of the Erez terminal and into Gaza, but no pedestrians were there because it was still early.

Shortly after the explosion, the Israel Air Force attacked a vehicle carrying several Palestinians that were apparently connected to the attempted attack. The IDF said two militants were killed in the strike, but Islamic Jihad said the men had managed to leap from their vehicle before it was struck.

Abu Ahmed, a spokesman for Islamic Jihad's armed wing, said the truck was carrying four tons of explosives. He identified the suicide bomber as 23-year-old Ibrahim Nasser from Jabalya in the northern Gaza Strip. The group released a video of Nasser, a young bearded man in uniform, smiling as he brandished a Kalashnikov assault rifle.

Hamas, which controls the Gaza Strip, said the vehicle was driven by a suicide bomber under cover of heavy early morning fog and that he was accompanied by gunmen.

"In terms of the amount of explosives used, Thursday's attack was the biggest since Israel pulled its settlers and troops out of Gaza nearly three years ago," IDF spokeswoman Maj. Avital Leibovich said. She could not confirm the militants' claim that the truck carried four tons of explosives.

Residents in the Gaza Strip who live over 30 km (20 miles) from the crossing reported hearing the blast.

Israel's Channel 10 television said troops had prevented the truck from getting close to the crossing by firing at it before it exploded.

Thursday's incident was one in a string of recent Palestinian militant attacks on Israeli crossings on the Gaza border. Last month, on the eve of Passover, Hamas gunmen wounded 13 Israeli soldiers in a well-coordinated assault by explosives-laden vehicles against the Kerem Shalom crossing.

One week prior, Gaza militants killed two Israeli civilian workers at the Nahal Oz crossing's fuel depot.

Israel has heavily restricted the movement of Palestinian people and goods through its border crossings with Gaza since Hamas seized the territory from Fatah in fighting last June.

"Israel must not let such attacks halt the flow of goods into Gaza," said John Ging, the Gaza director of the UN organization in charge of Palestinian refugees. "If you hand the agenda over to the extremists, then they are very happy about it. If it only takes one rocket to derail everything, then that's massive power," Ging said.

In Egyptian-mediated talks on a truce between Israel and Palestinian militant groups, Hamas has demanded the crossings be re-opened in return for a cessation of violence.

"Resistance is strong and we are not begging for calm," Abu Ahmed said after the attack.

Separately, but at the time of the bombing, IDF troops raided a village in the central Gaza Strip and shot dead a 63-year-old man, medical workers and Hamas said.

An IDF spokesman had no immediate information on the incident. Israel frequently carries out raids and air strikes in the Gaza Strip as part of what it describes as efforts to curb Qassam rocket fire at Negev towns.

The attack on Erez came as a Hamas delegation was returning to Gaza from Egypt after holding cease-fire talks. Hamas officials said Thursday that the round of talks failed, and blamed Israel for not accepting a proposed six-month truce. They spoke on condition of anonymity because the group had yet to make an official statement.

Israel charges that Hamas would only use a lull to rearm. Hamas officials have openly said this is their goal.

Abu Ahmad, the Islamic Jihad spokesman, said Thursday's bombing was meant to send a message to Israel that if it didn't "accept a truce, Gaza is not going to be a place where you will enjoy stability."