Tripoli, Lebanon - According to Lebanese security sources at least 17 people, mostly Lebanese soldiers, were killed Wednesday when an explosion hit a bus in the northern port city of Tripoli.

Chaos reigned at most hospitals in Tripoli, and calls for blood donations were being aired on local radio stations to help save some of the wounded.

Wailing women stood at hospital entrances waiting for word on their loved ones.

"I am waiting to hear if my brother, who was on the bus, was killed or wounded," one of the women told dpa near al-Nanini hospital in the city.

The explosion occurred during the morning rush hour in the banking street of the Tal neighbourhood of Tripoli, the sources said.

A Lebanese security official at the scene said, "The bomb was probably placed near the area where the bus stopped, and it was detonated from a distance via a remote-control device."

Another police officer at the scene said investigations were still ongoing to see if a booby-trapped case was placed inside the bus.

"We believe that the target of the explosion was the Lebanese Army soldiers who were on the bus, which was also carrying Lebanese civilians to their work in the area," the security official, who requested anonymity, told dpa.

The area around the explosion was cordoned off and only Lebanese Army officials were allowed into the area.

Tripoli has witnessed sectarian clashes in recent weeks that have seen dozens of people killed and wounded.

The city is also close to the Palestinian refugee camp of Nahr al- Bared, which witnessed deadly clashes last year between Lebanese troops and members of the al-Qaeda inspired group Fatah al-Islam.

A security source told dpa in Tripoli that a suspect was arrested at the scene and he was being interrogated.

Some security sources were pointing the finger at members of Fatah al-Islam, led by fugitive Palestinian leader Chaker al-Abssi, who has warned the Lebanese Army they would pay a dear price for ousting his militants from Nahr al-Bared last year.

The explosion also took place as Lebanese President Michel Suleiman was set to make a historic visit to Damascus, where the establishment of diplomatic ties will dominate talks with his Syrian counterpart Bashar al-Assad.

The two-day visit, beginning on Wednesday, is the first by a Lebanese head of state since Syrian troops withdrew from Lebanon in 2005 following the assassination of former premier Rafik Hariri.

The blast came a day after the new national unity cabinet, headed by Western-backed Premier Fouad Seniora, gained a vote of confidence in parliament.