Syria has accussed rebels opposed to President Bashar al-Assad of attacking Aleppo with a chemical weapon, killing 15 people.
The state-run SANA news agency said Tuesday the rebels fired a rocket with "chemical materials" on the Khan al-Asal area of the northern province.
Earlier Tuesday, the opposition Syrian National Coalition chose U.S.-educated former businessman Ghassan Hitto as provisional prime minister to administer the areas rebels have seized from Syrian forces.
Hitto received 35 of the 48 votes cast by members of the opposition coalition meeting in Turkey. He has lived in the United States for decades, but recently moved from Texas to Turkey to help coordinate aid to rebel-held areas.
More than 100 countries have recognized the opposition coalition as the legitimate representative of the Syrian people, including the United States, Britain, France and Turkey.
On Monday, Syrian warplanes fired missiles into northern Lebanon, a move the United States calls a "significant escalation" in the conflict between the Syrian government and rebels opposed to President Assad.
There is no word on damage or casualties from the shelling. This is the first time Syrian forces have fired at suspected rebel targets inside Lebanon, which is struggling to stay neutral in the Syrian civil war.
Earlier Monday, U.S. Secretary of State John Kerry said the United States does not oppose British and French efforts to arm the Syrian rebels.
Last week, France said it would work with Britain to send weapons to the rebels if the European Union does not ease its arms embargo.
EU foreign ministers plan to meet this week in Dublin to address the issue. Several EU members have expressed concerns that a flood of weapons into Syria would only add to the bloodshed.
The Britain-based Syrian Observatory for Human Rights said 110 people died in fighting across Syria on Monday.