MANILA (AFP) - At least six people died and 20 were missing after a small inter-island ferry sank in waters south of the Philippine capital, the coast guard said Sunday, the second sea disaster in three days. The MV Baleno-9, carrying 88 passengers and crew, began listing and went down just before midnight near Batangas City, the coast guard said. Ships in the area rescued 62 people. Six bodies were later recovered by the coast guard and 20 were still unaccounted for, a coast guard report said. Passengers told the coast guard that the roll-on ferry began taking on water from the bow ramp. This severely affected the stability of the vessel causing her to badly list and eventually sink, the coast guard report said. Coast guard spokesman Commander Armand Balilo noted that the ferry had sufficient life vests and life rafts and that this may have allowed more of those on board to survive. Coast guard chief Admiral Wilfredo Tamayo said it was still unclear why the ship apparently began to take on water. It did not hit anything. Our first finding is it ran into huge waves. This would have put pressure on the (bow) ramp but we still have to get more details. We are getting accounts from the survivors, he told local radio.