Lebanese security officials say armed supporters of rival factions have exchanged fire in the capital, Beirut, leaving at least nine people wounded.
The officials say supporters of Shi'ite militant group Hezbollah and a rival Sunni faction traded insults before Monday's gun battle began. They say the Lebanese army later deployed in the area to restore order.
Earlier, Hezbollah leader Hassan Nasrallah promised to comply with an Arab-brokered agreement that forbids all Lebanese factions from using weapons to achieve political goals.
In a televised address to thousands of supporters in Beirut, Nasrallah also said that Hezbollah does not seek to rule the country. But, he said the arms of the Lebanese state must not be used to gain revenge against Hezbollah or its allies.
This was Nasrallah's first public address since Lebanon's rival factions agreed last week to Qatari proposals for resolving the country's 18-month long political crisis.
Under the deal, the factions elected former army chief Michel Suleiman as Lebanese president on Sunday.
US President George Bush telephoned Mr. Suleiman Monday to congratulate him on becoming president. Mr. Bush reiterated his commitment to the government of Lebanon and invited the new leader to visit Washington.
President Suleiman has begun work on forming a national unity government. The pro-Western Cabinet of Prime Minister Fuad Siniora resigned Sunday, but will stay on in a caretaker role until a new administration is formed.