In the months after the bombing, though, some American officials have been persuaded that the Lebanese group played a role.

It is not affiliated with the Lebanese group Hezbollah or other groups using the name.

The letter claimed responsibility for the attack in the name of the Lebanese group.

"One just cannot hope to achieve anything without paying due attention to the rightful demands of the Lebanese groups involved," it said.

Hezbollah is the only Lebanese group which has not been disarmed since the end of Lebanon's 1975-1990 war.

And the Lebanese group is also considered skilled in staging ambushes in the territory it knows best.

Lebanese groups have yet to agree on a plan for the disarming.

"We can only help the Secretary General to encourage the Lebanese group to be more flexible and to release the hostages."

They share other Lebanese groups' ethnic Arab background and Arabic language.

Militant Lebanese groups released 10 Western hostages in late 1991.