BEIRUT Agence France Presse

— Lebanon was preparing yesterday plans to ask for United Nations help in its hunt for the still-unknown assassins of a senior army general, whose killing has worsened a festering political crisis. “The investigation is now in the hands of judicial authorities,” a military spokesman said, refusing to give any further details.

“We will not rest until the truth is revealed,” he added. The government of Prime Minister Fouad Siniora said it will ask a UN commission, which is already investigating a string of political murders, to help with technical assistance.

“The council of ministers has decided to instruct the prime minister to ask the UN secretary-general to provide (Lebanon) with technical assistance from the international investigation commission,” a statement said. The UN is probing the assassination of ex-Premier Rafik Hariri and of seven other anti-Syrian figures over the past three years. Judicial officials declined to discuss the probe into the murder Wednesday of Brig. Gen. Francois Al-Hajj, who was killed along with his bodyguard in a car bomb attack.

A police source said three Lebanese men had been arrested late Wednesday on the outskirts of the southern port city of Sidon. “They are being questioned in connection with the license plate of a BMW car, found on the site of the blast” in Baabda, southeast of Beirut, the source said on condition of anonymity.

Records from the motor vehicle department have shown that each one of the men had owned the car sometime in the past, but that there was no clear evidence to incriminate them, the source said.

The army has said a BMW packed with 30 kilograms (77 pounds) of explosives detonated as Hajj drove past, killing him and bodyguard Khairallah Hedwan. The Red Cross said eight people were wounded. It was not clear if the license plate found by investigators at the scene of the bombing belonged to the booby-trapped car that killed Hajj.

On Wednesday journalists saw security forces detain a bearded man near the bombing site and at least one newspaper, the respected As-Safir daily, suggested that Islamist militants could be behind the attack. No one has claimed responsibility for the killing.

Hajj, the army’s operations chief, gained prominence during a 15-week battle this past summer between the army and an Al-Qaeda-inspired Islamist group at a Palestinian refugee camp in northern Lebanon.

Several officials said his assassination was linked to the current crisis over the presidency and possibly the battle at Nahr Al-Bared camp, which ended in September. Hajj’s murder triggered a chorus of condemnation across the globe and warnings it could further destabilize Lebanon.