MANILA - THE four suspects in a Manila bank robbery in which 10 people were murdered in cold-blood may have been executed by police, the country's human rights head alleged on Monday.

Commission on Human Rights chairwoman Leila de Lima was quoted by local media as saying the suspects behind the May 16 massacre at the Rizal Commercial Banking Corp. in Cabuyao, just south of Manila, 'could have been rubbed out by policemen'.

Ms De Lima said witnesses interviewed by the commission's initial reaction team claimed three of the men were unarmed when slain by policemen last Thursday, the ABS-CBN television website said in a posting.

'The policemen fired more shots when the suspects were already lying down,' Ms De Lima said, quoting testimonies of witnesses to the killings in the village of Pagaspas, near Tanauan City south of Manila.

Ms De Lima - who recently took over as head of the government-funded rights body - said the agency has taken the witnesses under its protection and has asked the Department of Justice to put them in the Witness Protection Programme, according to ABS-CBN.

It also asked the Philippine National Police for the autopsy reports on the three suspects and has called on police to provide the names of the officers involved in the shooting.

Another suspect was also killed by policemen in another alleged encounter last Wednesday, the ABS-CBN website said, adding that Ms De Lima claimed the commission had information that he was taken by officers before his death.

Police claim 20 million pesos (S$680,256) was taken in the robbery, although the bank has never confirmed this. -- AFP