Lebanese Army soldiers transport containers which were removed from the ship Letfallah II, after it was intercepted off Lebanon's northern coast and diverted to Selaata port, north of Beirut April 28, 2012. [Photo/Agencies]

BEIRUT - Lebanese authorities have found weapons on board a ship intercepted in the Mediterranean which may have been trying to supply Syrian rebels, security sources said on Saturday.

They said the ship, the Letfallah II, was on its way to Lebanon's northern city of Tripoli when it was intercepted and taken to Selaata port, north of Beirut, for inspection.

An overnight search uncovered weapons including rocket-propelled grenades and rifles in three freight containers, the sources said.

The Sierra Leone-flagged ship had sailed from Libya, via the Egyptian port of Alexandria, the sources added.

Syrian authorities have repeatedly said weapons are being smuggled from neighbouring countries, including Lebanon, to arm rebels fighting President Bashar al-Assad.

Lebanon's mainly Sunni Muslim city of Tripoli has seen frequent demonstrations in support of anti-Assad protesters and insurgents. There have also been armed clashes between minority Alawites - from the same sect as Assad's ruling family - and majority Sunnis.