A recently fired police officer in the Philippines took a busload of Hong Kong tourists hostage and killed eight of them during a 12-hour standoff, before police charged onto the bus and ended the ordeal.

The hijacker opened fire on passengers as police stormed the bus. But at least seven of the 15 tourists on board survived the ordeal, police Senior Superintendent Nelson Yabut said. Four hostages escaped by crawling out the back door.

The hijacker was killed by a police sniper, Yabut said, after he injured another police sharpshooter.

Nearby hospitals said they received the bodies of seven hostages. Of the survivors, one remained in critical condition, two more were in serious condition and five others escaped uninjured.

Police stormed the bus Monday evening in Manila after gunshots rang out from the bus, Yabut said.

Ambulances surrounded the bus after police regained control of the vehicle, 12 hours after the ordeal began.

Police officer Roderick Mariano said the bus driver, who escaped the massacre, told police the hostage-taker opened fire on the tourists.

The hostage-taker was a dismissed policeman armed with a M16 rifle. He seized the bus to demand his job back.

He was identified as former Senior Inspector Rolando Mendoza, 55.

According to 2008 newspaper reports, Mendoza was among five police officers charged with robbery, extortion and grave threats based on the complaint of a local hotel chef.

Along with the return of his job, Mendoza demanded his son, a police officer, be brought to him. He delivered his messages via handwritten notes, which he plastered on bus windows.

The standoff shocked the country, led Chinese officials in Hong Kong to issue a travel warning for the Philippines, and raised questions about the ability of police there to handle hostage-takings.

"How can I be satisfied when there were people who died?" Philippine President Benigno Aquino III said.

Earlier, the gunman released nine hostages, leaving 15 left inside the bus. Negotiations between the gunman and police took place during the day but tensions escalated throughout the evening.

Police eventually gained entry to the bus by bashing in the door, windows and windscreen with a hammer after Mendoza opened fire on the hostages.

The standoff was covered on live television and many locals criticized that decision, freelance reporter Carlos Conde told CTV News Channel from Manila.

Hostage-takings are not unheard of in the Philippines. Two years ago, a man took a busload of children and teachers hostage near the site of Monday's standoff, to protest corruption. That incident ended peacefully.

With files from The Associated Press