BEIRUT – The U.S. embassy in Beirut has warned citizens of a security threat in Lebanon in the first half of October, linking the heightened risk to the end of the Islamic fasting month of Ramadan.

The embassy said in an Oct. 3 message posted on its website that it was reviewing its own security in light of the concern.

“The U.S. embassy is concerned about the potential for groups or individuals to exploit the end of the holy month of Ramadan to undertake violent actions targeting Americans,” the message said. “The period of highest concern is the first half of October,” it added.

Ramadan, whose dates are determined by the lunar calendar, ended last week.

U.S. Deputy Assistant Secretary of State David Hale raised worries over Islamist militancy in north Lebanon during talks with Lebanese leaders over the weekend, according to Lebanese sources who attended his meetings.

A U.S. diplomatic car was targeted by a bomb in January in an attack which killed three Beirut residents.

In the last two months the Lebanese army also been targeted twice by bombs. The attacks in the predominantly Sunni Muslim city of Tripoli in north Lebanon have killed 14 soldiers and eight civilians. Syria has also warned of growing Islamist militancy in the north.

The United States aims to strengthen Lebanon's army and on Monday signed agreements to provide $63 million in military aid, according to statements by the Lebanese army and U.S. embassy.

The latest aid, part of $410 million of military assistance committed by the United States since 2006, covers communications and ammunition and weapons supplies for the infantry, they said.

Lebanese Defence Minister Elias al-Murr and Mary Beth Long, assistant U.S. defence secretary for international affairs, signed the agreements during the first meeting of a joint defence committee in Beirut.

The United States has been a firm backer of Lebanese opponents of Hezbollah, an Iran- and Syria-backed movement which Washington lists as a terrorist group.

Hezbollah – a political and military group – and Washington's allies in Lebanon joined a national unity government in July, easing a deep political conflict.

(Writing by Tom Perry; Editing by Dominic Evans)