BEIRUT - Libya severed diplomatic relations with Lebanon on Wednesday following accusations that Libyan leader Moamer Kadhafi helped cover up the disappearance of a prominent Shiite Muslim cleric, officials here said.

"Lebanese authorities have been informed that Libya has cut diplomatic relations with Lebanon," a senior Lebanese official told AFP, adding that Libyan embassy employees were expected to leave the country Thursday.

He said the move came after Lebanese religious and political officials accused Kadhafi of withholding information on the fate of Imam Mussa Sadr, who went missing on a trip to Libya in 1978.

Officials at the Libyan embassy were not available for comment.

Lebanon was informed of Tripoli's decision by the Libyan charge d'affaire in Beirut, another official said.

On Saturday, a group of Sadr's followers delivered a petition to the Lebanese government demanding it take up the case against Libya at the international courts.

The petition accused Kadhafi of being responsible for the imam's disappearance and of "having personally admitted in 2002 that Imam Sadr had been killed in Libya".

The same day, parliamentary speaker Nabih Berri called on the government, the United Nations, the Arab League, and humanitarian aid organizations to help determine the fate of the imam.

He demanded that "the Lebanese government take up the matter ... in order to learn the truth about the fate of the imam and his two companions", a sheikh and a Shiite journalist who also disappeared.

The imam was the head of the Shiite Higher Council, the most important body in the Lebanese Shiite community, of which his Amal movement and the rival Hezbollah movement are the largest political factions.

Tripoli has always denied any responsibility in the imam's disappearance, claiming that he and his companions had traveled to Italy at the end of their stay in Libya.

On the anniversary of Sadr's disappearance Sunday, Sayyed Hassan Nasrallah, the head of Hezbollah, called on Kadhafi to admit personal responsibility for the imam's case.

"Kadhafi, personally, knows the fate of Imam Mussa Sadr," Nasrallah told a rally in Beirut's southern suburbs.

Nasrallah also referred to the recent settlement in which Kadhafi agreed to pay out 2.7 billion dollars (2.5 billion euros) in compensation for the bombing of a Pan Am airliner over Lockerbie, Scotland, in 1988.

"The Kadhafi regime and Kadhafi personally are standing up to explain how they got to resolve these issues ... and how they paid billions of dollars, but what is more important ... is to assume the responsibility," he said.

"If he is truly speaking about courage and wisdom ... then let him have the same courage to disclose the fate of Imam Mussa Sadr and bear responsibility for this issue," Nasrallah said.

Last year, Lebanon dispatched a government minister to Tripoli to invite Kadhafi to the annual Arab League summit which it hosted that March.

But the minister returned home without being able to meet with Kadhafi, who eventually failed to attend the summit and sent instead a high-ranking delegation.