Hundreds of trucks have been held up at a border crossing between Lebanon and Syria amid heightened security measures enforced as the Syrian regime faces unprecedented protests.
"Between 400 and 500 trucks, most with Syrian or Jordanian licence plates, have been held at the Abboudiyeh border crossing for hours for inspection by Syrian security forces," a Lebanese security source told AFP.
"The inspection of each truck is taking about one hour," he added. "These measures have been in place for three days."
The Abboudiyeh crossing in northern Lebanon leads to the central Syrian industrial city of Homs.
Thursday's security measures, the toughest in years, come amid accusations by Damascus that members of caretaker Sunni premier Saad Al-Hariri's Western- and Saudi-backed Future Movement have been funding and arming anti-government protesters in Syria.
Syrian state television on Wednesday aired "testimonies" of three people saying they had received funds and weapons from Sunni MP Jamal al-Jarrah to fuel a wave of protests against the ruling Baath regime.
Jarrah has denied the allegations.
Protests erupted in Syria on March 15 calling for an end to a decades-old state of emergency and demanding sweeping reforms.
Activists and human rights groups estimate more than 100 people have been killed and scores wounded in the demonstrations, which have spread to cities across the country.
Damascus was forced to pull its troops out of Lebanon in 2005 following a 29-year presence.
The withdrawal came in the face of massive international pressure over the 14 February 2005 assassination of ex-premier Rafiq Al-Hariri, Saad's father.
Syria has denied accusations it was involved in the killing.
In 2006, trucks along the Syrian-Lebanese border were also held up in what was thought to be a retaliatory measure by Syrian authorities amid tension between the two countries.
Lebanon and Syria agreed to establish diplomatic ties in October 2008, for the first time since the two countries' independence from France 60 years ago.