Lebanon's attorney general has confirmed receiving warrants summoning two prominent Lebanese MPs to appear before a military court in Syria.
Walid Jumblatt is one of the main figures in Lebanon's anti-Syrian camp
The MPs are Druze leader Walid Jumblatt and telecoms minister Marwan Hamade.
Reports say Mr Jumblatt, a key member of the anti-Syrian camp in Lebanon, is accused by Damascus of "inciting against Syria".
A third man, Lebanese journalist Fares Khashan, has also been summoned to appear before a Syrian Military court.
Mr Jumblatt is an outspoken critic of Syria. He has recently accused the Syrian government of "taking part in terrorism", and on Thursday offered to help exiled Syrian opposition groups work towards a "democratic and free" Syria.
Mr Hamade was the target of a failed assassination attempt in 2004. It is not known who was behind the attack.
Mr Khashan is a regular critic in the Lebanese press of the Syrian government and its supporters inside Lebanon. According to the Lebanon's National News Agency, he is currently outside Lebanon.
BBC Arabic Service correspondent in Beirut, Nada Abdul Samad, says the warrants issued against the three men are seen as part of the struggle in Lebanon between pro-Syrian and anti-Syrian factions in Lebanon.
The killing of former Lebanese Prime Minister Rafik Hariri in a truck bombing on 14 February 2005 prompted huge street protests and the withdrawal of Syrian forces stationed in Lebanon.
Damascus denies any involvement in the assassination.