A handout photo taken on Thursday by Kaohsiung Police Department shows armed policemen standing guard over the bodies of hostage takers at the Kaohsiung Prison in southern Taiwan. Six prisoners committed suicide, ending a standoff after they took several staff hostage to complain about unfair jail systems. Photo: AFP

 The Taiwan justice department said improving guard management is their top priority after an overnight hostage incident in a Kaohsiung prison ended with six inmates killing themselves early Thursday morning.

Chen Ming-tang, the deputy justice chief, said Thursday that all prison guards were called back to Kaohsiung city prison since the incident broke out. He said the prison environment is currently stable and added that improving the management of guards is now the top priority.

Taiwan leader Ma Ying-jeou also urged the justice department to hand in an investigative report on the hostage incident as soon as possible while authorities must review management procedures to examine loopholes exposed by the incident Thursday.

According to Chen, the department will release a review of prison management Friday while a detailed report about reform measures will be finished within a week.

Chen also pointed out that Taiwan prisons are facing a serious human resources problem, as there are 63,000 inmates but only 8,000 prison guards.

The prison hostage incident broke out Wednesday afternoon when the six inmates pretended to seek medical attention and took several guards hostage as they attempted to escape, starting the 14-hour standoff.

The six inmates had been convicted of burglary, murder and drug crimes and were all serving long sentences. They took four rifles, six handguns and more than 200 bullets from the prison's armory and demanded safe passage from the jail.

During a phone call with local media, the inmates revealed that the hostage incident was pre-planned.

Negotiations ran through the night and the inmates agreed to release the hostages in exchange for the prison chief and a senior staffer.

Prosecutor Chen Chun-hsiu, who led the negotiations, said the inmates knew they would spend the rest of their lives in prison and had intended to kill themselves all along.

"They had expressed their determination to die from the beginning of our communication ... they felt that they were not given fair trials and they doubted whether they would ever be released from prison. They were determined a long time ago to end the protest with their deaths," he told reporters.

One of the six, Cheng Li-teh, a top member of a triad group known as the Bamboo Union Gang, who was sentenced to 28 years for murder, wrote a letter in which he questioned whether it was fair to release former Taiwan leader Chen Shui-bian on early medical parole, while other inmates suffering serious illnesses were not afforded the same treatment.  Chen Shui-bian, who was found guilty of corruption offenses in November 2010 and sentenced to eight years, was released on parole on January 5.

This parole has been extended until May. 

Chiu Yi, a Kuomintang member and former legislator, told the Global Times earlier when Chen Shui-bian was about to be granted medical parole, that once he was released, there could be a strong likelihood of prison riots, as other inmates would also make similar requests and feel discriminated against if rejected.

Cheng also complained about the current prison regime, which only gives prisoners NT$200 ($6.32) a month, which he said is not even enough to buy underwear.

The standoff ended at around 5 am Thursday. Dozens of gunshots were heard, four inmates shot themselves and the other two did the same about 20 minutes later, according to local media.

The hostages were unharmed and walked out later.

"Police and prosecutors on the scene tried to persuade them to surrender and not to take their lives but they would not listen. We regret that they committed suicide," said Chen Ming-tan.

Ma also said that he "deeply regretted" that the six prisoners took their lives.

Chang An-lo, also known as White Wolf, the leader of the Bamboo Union Gang, tried to negotiate with Cheng before the inmates killed themselves. He said that Cheng's death exposed prisoners' disagreement with the current prison management system.

Chang is not currently in jail.

"He [Cheng] was angry because Chen Shui-bian, a graft convict, could be released," he told the Global Times, adding that other prisoners he knows feel the same way.

He said that police did not let him enter the prison and that if he could have entered, the hostages may have been released earlier and the inmates might not have killed themselves. It is not known if all six inmates were gang members.

"The police may have thought that it would shame them if a gang leader could solve a problem that they could not," he said.