"The three men were caught in possession of vials containing unknown substances which have been sent to a laboratory to determine their contents," a judicial official told AFP on condition of anonymity.

"The military judge has accused them of possession of illegal substances and has ordered their detention," the official said.

The three were arrested in the Kfar Shuba district in southern Lebanon, local press reported, though the date of their arrests was not specified.

"The accused are not linked to the attacks that recently took place in Tripoli," the official said referring to two bus bombings that targeted Lebanese soldiers leaving over two dozen people killed.

On Sunday, Lebanese authorities announced the arrest of a "terrorist network" thought to be behind three deadly attacks against the army since May.

The cell is thought to be linked to the Al-Qaeda inspired Fatah al-Islam militia, that fought a deadly 15-week battle with the army in the Nahr al-Bared Palestinian refugee camp in northern Lebanon last year, a security official said. -AFP