At least 20 people are now known to have been killed when a powerful explosion ripped through an exclusive club in the Colombian capital, Bogota. Investigators say the blast was caused by explosives - possibly a car bomb placed in an indoor car park at the Club Nogal, which is frequented by Colombia's political elite and foreign diplomats. More than 110 people were injured in the blast, which blew the facade off the 10-storey building scattering debris over Seventh Avenue, the city's main street, which was crowded at the time with revellers or people heading home. Firefighters are working to reach survivors believed to be trapped on the sixth to eight floors and to put out the blaze.