"At the gate of the U.S. embassy in Awkar, army forces arrested a Lebanese man and a Palestinian accompanying him as they tried to bring a bomb into the embassy complex," the army said in a statement.

"Investigations have begun with them and work is ongoing to arrest all those involved and bring them to justice," the statement said. A Lebanese security source said soldiers searched a man, in his 30s, carrying a sports bag at the external entrance of the embassy and found 2.2 pounds of explosives inside. He said shortly after the incident a Palestinian man was arrested in the area on suspicion of links to the detained man

Witnesses said the heavily fortified hilltop embassy, which limits the movement of its staff for security reasons, remained open after the incident.

EMBASSY GUARDS SOUNDED ALERT

The U.S. embassy confirmed the army had arrested the man at its gates after U.S. embassy guards alerted Lebanese authorities of a suspicious person.

"A person with a suspected improvised explosive device tried to get to the embassy. Embassy guards found him suspicious. ... The Lebanese army forces arrested him," an embassy source said.

Another U.S. embassy source said the man apparently wanted to leave the explosives at the embassy and walk away. She said she was unaware of the second arrest.

Monday, Lebanon formally charged 10 people with "terrorist" links over a string of bombings against American fast food outlets over the past two years and a plot to kill U.S. ambassador Vincent Battle. Some of those arrested are believed to be linked with Osama bin Laden's al Qaeda network.

Lebanon was the scene of dozens of anti-U.S. groups sponsored and protected by Syrian baath regime attacks in the 1980s with suicide bombings against the U.S. embassy, its annex and the main Marine barracks in which hundreds were killed. Several U.S. nationals and other Westerners were also kidnapped.

The attacks abated after the end of the Lebanese civil war in 1990. But a series of much smaller attacks have targeted mainly U.S. and British interests since the eruption of a Palestinian uprising against Israeli occupation three years ago and the U.S.-led invasion of Iraq in March.