Lebanon - The UN tribunal investigating the assassination of the former Lebanese PM Rafik Hariri in 2005 has said it will try the four accused in absentia.

Shia Islamist group Hezbollah members were named as suspects and warrants for their arrest issued last summer.

But its leaders have refused to hand them over and the Lebanese authorities have not been able to arrest them.

Hezbollah denies any role in the killing of Hariri and 21 others in Beirut in February 2005.

The Special Tribunal for Lebanon (STL) issued a statement detailing the steps taken by the Lebanese authorities to apprehend the accused.

These included multiple attempts by the Lebanese authorities to find the accused at their last known residences, places of employment, family homes and other locations, it said.

"The trial chamber concluded that all reasonable steps have been taken to secure the appearance of the accused and to notify them of the charges against them," the Hague-based court said in a statement.

It did not say when the trial would start.