Loud explosion heard near besieged Pakistani mosque

ISLAMABAD, July 5 (Reuters) A loud explosion was heard today in the vicinity of a besieged mosque in the Pakistani capital, where hundreds of militant Islamic students were locked in a deadly stand-off with security forces.

Reuters journalists close to the mosque could see no sign of paramilitary troops preparing to launch an assault.

The explosion followed half an hour of sustained gunfire, after an earlier lull. At least 17 people have been killed in clashes that began on Tuesday.

Reuters AGL DB2004