A loud explosion ripped through an apartment in a busy, upscale district of the Philippine capital on Friday night, and a radio report said at least three people were killed by falling debris that hit a passing delivery van. Police said they were investigating what caused the blast in Manila’s Serendra district, a shopping and residential area that was teeming with passersby. Officials could not immediately confirm any casualties. TV footage showed a large hole in an apartment in a residential building and a wrecked vehicle nearby which was apparently hit by debris. DZBB radio station reported at least three fatalities in the delivery van. Broken glass from windows in retail shops littered the street. Joel Montales, an administrator of Taguig city, where Serendra is located, told ABS-CBN TV that police, fire and rescue teams were in the area to help treat possible casualties and determine the cause of the blast.