MANILA, Philippines — Philippine police in helmets and flak jackets crouched beside the bus on Monday, after firing shots at the tires in a bid to end a day-long hostage standoff involving 15 Chinese tourists.There was no immediate word on casualties.RELATED:Gunmen hold hostages in Pakistan army headquartersPolice said they fired at the tires to immobilize the vehicle.Moments later, a Filipino driver was seen during live TV footage late Monday running away from the bus. Police commandos then surrounded it and were seen breaking the door and windows with a hammer, though they still did not enter the vehicle.Earlier in the day, a dismissed policeman armed with an automatic rifle had seized a bus in the Philippine capital with 24 passengers, most of them Hong Kong tourists, in a bid to demand his reinstatement, police said.Seven hostages, including three children, were subsequently released unharmed. A senior Chinese diplomat who was monitoring the negotiations to free the remaining 17 hostages said they were "calm and peaceful.""We want everything taken to secure the safety and security of our Chinese nationals," Bai Tian, deputy mission chief at the Chinese Embassy, told reporters.The hostage-taker, identified as former Senior Inspector Rolando Mendoza, 55, was armed with an M16 rifle. He demanded that he be given back his job on the police force a year after he was fired, Manila police chief Rodolfo Magtibay said.Two of the Hong Kong tourists, both women, were the first to be released, followed by a girl, two boys and their mother as well as their Hong Kong guide, Magtibay said. A seventh hostage freed was suffering from diabetes, police said. Police brought in food for the hostages and prepared to provide fuel so that the air conditioning unit can keep running as the outside temperature reached about 32 degrees Celsius.In March 2007, not far from Monday's hostage taking, a man took a busload of children and teachers hostage from his day-care center in Manila to denounce corruption. They were freed after a 10-hour standoff.