Tension was mounting in Beirut on Tuesday, with several streets and schools shut and military checkpoints set up following the issuing of a confidential draft indictment for the assasination of former premier Rafik Hariri, DPA reported.
Security officials said supporters of the Shiite movement Hezbollah were seen milling about the streets of the capital, where Hariri was killed in a car bomb blast in 2005.
A security source told the German Press Agency dpa that dozens of Hezbollah "militia" were gathered near schools, prompting concern among parents.
"This was an attempt to cause panic among the Lebanese and close schools," the source said.
Some lawmakers expressed concern that violent protests could erupt. But Hezbollah lawmaker Ali Khreiss, speaking on Voice of Lebanon radio, said "no decision to take street action" had been taken.
Speculation that the Special Tribunal for Lebanon (STL) is targeting members of Hezbollah prompted its members and their allies to withdraw from the cabinet last week, leading to the collapse of the country's national unity government.
On Monday, STL Prosecutor Daniel Bellemare submitted his long- awaited indictment to the pre-trial judge Daniel Fransen, who must now confirm the charges before any arrest warrant or summons can be issued.