Several explosions were heard near a radical mosque besieged by security forces in the Pakistani capital Thursday, hours after its top cleric was captured trying to sneak out of the complex disguised in a woman's burka. It was not immediately clear what caused the series of heavy blasts, which lit up the sky near Islamabad's Lal Masjid, or Red Mosque, before dawn between bursts of gunfire. Troops ringing the mosque pushed reporters far back from the area.