The United States and Arab allies rushed military aid to Lebanon, boosting its strength ahead of a possible army assault to crush al-Qaida-inspired Islamic militants barricaded in a Palestinian refugee camp. The US aid is sensitive in a nation deeply divided between supporters of a pro-Western government and an opposition backed by America's Mideast foes, Iran and Syria. The opposition, led by the Shiite Hezbollah, accuses the government of Prime Minister Fuad Saniora of being too closely allied to Washington. Palestinian factions were scrambling to find a negotiated solution to end the siege and avert what many fear would be a bloody battle over Nahr el-Bared, where thousands of civilians remain in the line of fire. Lebanese Defense Minister Elias Murr said he was "leaving room for political negotiations," which he said must lead to the surrender of the fighters from the Fatah Islam militant group inside the camp. "If the political negotiations fail, I leave it to the military command to do what is necessary," he told reporters. The military was gearing up for a fight, rolling more troops into place around the camp in northern Lebanon, already ringed by hundreds of soldiers backed by artillery and tanks. Fatah Islam has claimed to have over 500 fighters, armed with automatic weapons, mortars and rocket-propelled grenades. At least a dozen more armored carriers and a battle tank were seen headed for the area Friday. In a statement, the military warned the militants: "You have no choice but to surrender." Sporadic gunfire at Nahr el-Bared camp kept tensions high, but a truce that has halted three days of heavy artillery and rocket bombardment since Tuesday held. An all-out assault on the camp would risk sparking unrest and violence elsewhere in the country, where some 400,000 Palestinian refugees live, most in camps that are rife with armed groups. A deputy Fatah Islam leader, Abu Hureira, told the pan-Arab Al Hayat daily by telephone from Nahr el-Bared that "sleeper cells" in other Palestinian camps and elsewhere in Lebanon were awaiting word for a "violent response" if the army struck. The US military aid could also attract other militants into what they see as a battle against the West and its allies. Extremist groups were already using the battle at the camp as propaganda. A group billing itself as al-Qaida's branch in Syria and Lebanon vowed "seas of blood" if the Lebanese army resumes its attack. In a video posted on the Web Friday, a spokesman for the group threatened bomb attacks on Lebanon's vital tourist industry. Earlier, a Palestinian group called the Army of Islam also threatened attacks. The capabilities of the two groups are not known. The airlift from the United States and Arab countries boosts the military in what could be a tough urban battle inside the camp, a densely built town of narrow streets. Between late Thursday and early afternoon Friday, five military transport planes landed at Beirut airport, including one from the US Air Force, two from the United Arab Emirates and two from Jordan. The military said it received supplies from Arab countries and the US but gave no details; media reports said they included ammunition, body armor, helmets and night-vision equipment. US military officials said Washington would send eight planes of supplies, part of a package that had been agreed on but that the Lebanese government asked to be expedited. "We are expediting deliveries of planned US military assistance to the Lebanese armed forces as well as enlisting the support of international partners to provide additional assistance," said Dave Foley, a State Department spokesman. White House spokesman reiterated US support for Saniora's government. "The most important thing for us is that the Saniora government be able to continue building itself effectively," he said. About half of Nahr el-Bared's population of 31,000 fled the camp during the truce, flooding into the nearby Beddawi camp. At least 20 civilians and 30 soldiers were killed in the fighting earlier this week. The Lebanese military says 60 Fatah Islam fighters were killed, though the group put the toll at 10. The truce also gave Palestinian mediators a chance to maneuver. But prospects for a peaceful settlement appeared dim, with the government determined to finish off the militants, Fatah Islam vowing to fight to the death and major Palestinian factions unable to agree on how to take charge of camp security. "We want a solution that pleases both sides. We don't want dead people on both sides," said Ghassan Ahmed, 35, a camp resident who was hospitalized with shrapnel in the leg and arm. "They should send Fatah Islam to another country. Maybe there they can find another life."