AMMAN (Reuters) - A car bomb killed a schoolgirl on Monday and wounded 25 others at a school in the southern Syrian city of Deraa, the scene of sporadic street fighting between Free Syrian Army rebels and President Bashar al-Assad's troops, an opposition activist said. "The car exploded at nine in the morning in al-Kashef neighborhood in front of al-Mahatta High School for Girls, which has been active in (anti-Assad) demonstrations," Maher Abdelhaq told Reuters from the city on the border with Jordan. (Reporting by Khaled Yacoub Oweis in Amman; Editing by Louise Ireland)