Syrian opposition groups have elected a moderate cleric, Maath al-Khatib, to lead a new coalition uniting the disparate factions fighting to oust President Bashar al-Assad.

Khatib is a former imam at the Umayyad mosque in Damascus and was imprisoned several times for criticizing Mr. Assad's rule before leaving Syria this year.

Opposition members also voted Sunday in Doha to elect businessman Riad Seif and well-known female activist Suhair al-Attasi as vice presidents.

Seif proposed the U.S.-backed initiative to establish an umbrella organization for the opposition both inside Syria and abroad. Anti-Assad figures had struggled to achieve unity under pressure from U.S. diplomats and officials from Qatar, which have supported Syrian opposition activity since an uprising began last year.

The U.S. State Department said in a statement late Sunday that it looks forward to supporting the united opposition as it works “toward the end of Assad's bloody rule” and a peaceful, democratic future in Syria.

The agreement Sunday came after the group formerly seen as the main representative of the opposition, the Syrian National Council, heeded Arab and Western pressure to agree to a new structure embracing those who had been unwilling to join its ranks.

Meanwhile, Israeli troops fired warning shots into Syria after stray munitions from fighting between Syrian troops and rebels landed in Israel's Golan Heights area.

The military said in a statement Sunday that a mortar shell landed near an Israeli army post in the Golan Heights. It says that Israeli soldiers fired warning shots in response.

The statement adds that the army filed a complaint through the local U.N. forces warning that “fire emanating from Syria into Israel will not be tolerated and shall be responded to with severity.”

U.N. Secretary-General Ban Ki-moon said he is deeply concerned for potential escalation in the area and called for both sides to exercise restraint.

Israel public radio said the incident was the first direct engagement between Israel and Syria since the countries' 1973 war.