Palestinian militants vowed Friday to avenge Israel's assassination of the Hamas government's top security chief in an attack that threatened to ignite large-scale violence between the two sides.

Palestinians carry the body of the Hamas government's security chief and leader of the Popular Resistence Committees, Jamal Abu Samhadana, 45, after he was killed by an Israeli airstrike late Thursday June 8, 2006. [AP]

The security chief, Jamal Abu Samhadana, was a key player in Palestinian rocket attacks against Israel and a close ally of the Hamas militants who now govern the Palestinian Authority and have refused to renounce their commitment to Israel's destruction.

Hours after his death Thursday night, Palestinians in the Gaza Strip fired two rockets into Israel, hitting a building in the southern town of Sderot, but causing no casualties, the military said. No one claimed responsibility.

Abu Samhadana's appointment as Hamas' top enforcer not only angered Israel but helped set the stage for recent Palestinian infighting that has killed 16 people. The conflict has raised the specter of all-out civil war between Hamas and the Fatah movement the Islamic militants unseated in January parliamentary elections.

Palestinian President Mahmoud Abbas of Fatah, who is eager to restart long-stalled peace talks with Israel, was expected on Saturday to announce a date in late July for a national referendum on establishing a Palestinian state alongside Israel.

Hamas government officials called Abu Samhadana's killing a direct assault on the Palestinian Authority, and vowed to continue its resistance against the Jewish state. Abu Samhadana's Popular Resistance Committees faction vowed revenge.

"God willing, our retaliation shall come," blared a loudspeaker on a car carrying Abu Sharif, a top PRC commander, as it toured Gaza streets shortly after Israel's airstrike.

"It will not be by statements, but by rockets toward Sderot and all the Zionist community. It will be by self-sacrificing martyrs who will blow up themselves in every corner."

Israeli police spokesman Micky Rosenfeld said Friday that security officials were aware of threats of revenge and were taking general precautions. He did not elaborate.

The Israeli military said it struck a PRC training camp in the southern Gaza town of Rafah because militants there were planning a large-scale attack on Israel. It would not confirm or deny that Abu Samhadana, the No. 2 man on Israel's wanted list, had been the target.

Abu Samhadana, 43, was an explosives expert and a suspect in the fatal 2003 bombing of a U.S. convoy in the Gaza Strip. He said Israel targeted him five years ago in an explosion that left his right arm burned and mangled.

He and other militants had been about to enter the training camp in the former Jewish settlement of Rafiah Yam when the four missiles struck, killing him and three other militants, and wounding 10.

Palestinian factions, including Fatah, condemned his killing, and said it would only fuel attacks on Israel.

Ghazi Hamad, a government spokesman, said Israel's targeting of a key government figure raised the likelihood of "dangerous consequences and developments."

Since Hamas was elected to power in January, it has not been directly involved in attacks against Israel, but it does back other factions' operations. Hamas is thought to help finance the PRC, and an estimated 500 people belong simultaneously to both groups.

Over the past week, Hamas members have cooperated with the smaller group in firing rockets at Israel, though Israel has said Hamas leaders did not dispatch them.

Thousands of mourners, shouting "Revenge, revenge," marched to the morgue where Abu Samhadana lay. His body was bundled onto a stretcher, hoisted over the crowd's shoulders, and paraded around the hospital compound before being returned to the morgue ahead of Friday's funeral.

One weeping Popular Resistance fighter compared Abu Samhadana's assassination to the killing of Abu Musab al-Zarqawi, the al-Qaida in Iraq leader, by U.S. forces on Wednesday.

"This is a big blow to Islam and the holy warriors," said the man, who refused to identify himself. "We hope that God will send us more heroes."

Reaction to Abu Samhadana's death swept through the Rafah refugee camp where he had lived, bringing out nearly all its thousands of residents.

"I feel humbled because men like him gave their lives as a price for their beliefs, and to defend us," said Ibrahim Atwan, 45. His wife, Iman, said she hoped one of her children would "follow in his footsteps."

Abu Samhadana had moved stealthily, switching cars and hideouts. A few days before his death, he told The Associated Press in a back alley interview that the U.S. government and its people would "pay a dear price" for leading bruising economic sanctions against the Palestinian Authority.

The U.S. and other Western countries imposed the sanctions because of Hamas' refusal to disarm militants and recognize Israel.

"We are happy when any American soldier is killed anywhere in the world, because the American Army is an aggressor against all the people in the world, particularly the Arab and Muslim worlds," he said. "The American people are known to be peaceful, so they are asked to move to bring down this terrorist government in Washington."

He said he had taken security measures against an Israeli attack, adding with bravado, "They don't catch me. I hunt them."

Abu Samhadana graduated from a military school in communist East Germany in 1988. He was loyal to Yasser Arafat for many years, but was later expelled from Arafat's group Fatah.

He formed the PRC with militants from various factions after the latest Palestinian uprising broke out in 2000.