MANILA - Blunders in the deadly end of the Philippine's hostage crisis are just the latest black mark for its police force, which has long been hounded by accusations of torture, murder, corruption and ineptitude.

The bloody conclusion to Monday's hijacking highlighted a myriad of problems within the much-maligned force of 135,000, according to human rights advocates, the Philippine media and security experts.

"There is something wrong with the national police. It is viewed more as a source of livelihood for the policemen rather than an institution to protect law and order," human rights lawyer Harry Roque told AFP.

The latest tragedy began when an ex-policeman hijacked a busload of Hong Kong tourists, demanding to be reinstated after he was sacked for extortion.

After muddled attempts to negotiate his surrender, the rogue policeman began shooting, prompting the police to storm the bus. But it still took more than an hour before they penetrated the vehicle and killed the hostage-taker.

The poor response left eight Hong Kong tourists dead, the police force admitting to making mistakes and a public aghast at how poorly the security personnel performed.

"Someone should have the sense of honour to say: 'This is a blunder, this is a national shame. I should resign,' but nobody does," said Manila-based Augustus Esmeralda, president of Ace and Associates security consultancy firm.

The police said in a statement that its mistakes included poor negotiations tactics with hijacker Rolando Mendoza, inadequate equipment for the commandos, allowing the media to roam around the hostage site and bad crowd control.

Four policemen who led the bungled assault were on Wednesday suspended pending an inquiry.

But national police spokesman Superintendent Agrimero Cruz insisted the tidal wave of anger directed at the force was "unfair".

"They are all in the gallery, watching," he said of the critics. "They should try being in the line of fire and let us see how they react."

Nevertheless, Interior Secretary Jesse Robredo, who is in charge of the police, conceded that the hostage crisis highlighted many deep-rooted problems, such as lack of proper equipment, training and resources.

"It's a combination of all these factors. All the inadequacies came together," Robredo told reporters.

Philippine media outlets have also been critical, saying the crisis exposed many of the shortcomings within the force.

"(The hostage-taker's) caper gives added urgency to the need for a thorough housecleaning in the Philippine National Police," the Philippine Star newspaper said in its editorial on Wednesday.

Roque said one of the force's biggest problems was corruption.

There have been many accounts of prospective recruits paying bribes to join the service, and paying again to get important posts with the express intention of using their positions to make money, Roque said.

Aside from the corruption, the practice leads to incompetent policemen getting promoted, he said.

"It all ties together," Roque said.

The police force was already under fire a week before the hostage crisis, over a video showing policemen torturing a naked man in a Manila police station.

Eleven policemen were suspended after the video was aired on television.

Human rights lawyers also say the problem of police shooting suspects deliberately is a major concern, with the practice so prevalent that it has its own term -- "rub out".

The national human rights commission is currently investigating the case of a car thief who apparently died in custody after what police said was a shoot-out in Manila this month.

Initial tests indicated the suspect had not been armed.

Over 60 policemen are also accused of complicity in the massacre of 57 people in the southern province of Maguindanao in November last year in the worst case of political violence in the country's history.

Human Rights Watch's representative in the Philippines, Jessica Evans, said there was a "culture of impunity" among uniformed men who feel they are not accountable.

"A police force that feels it can break the law and not be accountable is going to have problems in general," she said.