TRIPOLI, Lebanon -- Gunmen loyal to opposite sides in neighboring Syria's civil war battled Wednesday in the streets of a northern Lebanese city where two days of clashes have killed at least six people and wounded more than 50, officials said.
The Lebanese army fanned out in the city of Tripoli in an attempt to calm the fighting, with soldiers patrolling the streets in armored personnel carriers and manning checkpoints. Authorities closed major roads because of sniper fire.
The fighting comes at a time of deep uncertainty in Syria, with rebels fighting government troops near President Bashar Assad's seat of power in Damascus.
In Brussels, U.S. Secretary of State Hillary Rodham Clinton reiterated concerns that "an increasingly desperate Assad regime might turn to chemical weapons" or lose control of them to militant groups.
She also said NATO's decision Tuesday to send Patriot missiles to Turkey's southern border with Syria sends a message that Ankara is backed by its allies. The missiles are intended only for defensive purposes, she said.
Turkey's foreign minister, Ahmet Davutoglu, was quoted Wednesday in the Turkish newspaper Sabah as saying that Syria has about 700 missiles, some of them long-range.
U.N. Secretary-General Ban Ki-moon on Wednesday also urged Syria's regime against using chemical weapons, warning of "huge consequences" if Mr. Assad resorts to such weapons of mass destruction.
Syria has been careful not to confirm that it has chemical weapons, but the regime insists it would never use them against the Syrian people.
Also Wednesday, U.S. officials said the Obama administration is preparing to designate a Syrian rebel group with alleged ties to al-Qaida as a foreign terrorist organization. The step seeks to isolate extremists within the Syrian opposition while the West tries to bolster those it supports.
The largely symbolic move will freeze any assets that members of the group, Jabhat al-Nusra, have in U.S. jurisdictions and bar Americans from providing the group with material support, the officials said.