The brutality of the mutiny by the Bangladesh Rifles soldiers continued to unfold on Saturday with the discovery of two more mass graves containing bullet- riddled bodies of army officers at its headquarters in Dhaka.

The two graves were unearthed by rescuers, a day after the first one with 42 bodies of massacred officers, including BDR chief Major General Shakil Ahmed, was found in the premises of the force's headquarters in Pilkhana area in the heart of the capital.

The death toll before the discovery of the new graves stood at 67. It was not immediately known how many bodies were there in the graves, even as over 70 army officers were still believed to be missing.

"We have discovered two new mass graves as we resumed our searches today morning," a Fire Brigade spokesman said.

Aided by sniffer dogs, security forces resumed the frantic search for more victims of the two-day revolt, which came to an end on Thursday with the surrender of the mutineers.

The Bangladesh government has announced that it will constitute special tribunals for quick and 'exemplary punishment of the culprits involved in the barbaric and gruesome killings of army officers' during the rebellion, despite an earlier promise of general amnesty.

"General amnesty does not mean that those (rebel BDR soldiers) who were involved in killings, rebellion, arson and other heinous activities will be forgiven," Prime Minister Sheikh Hasina's [Images] Principal Staff Officer Lieutenant General Mohammad Abdul Mubin said in a nationwide televised statement shortly after midnight.

He promised fast track trial of culprits involved in the killings of army officers during the rebellion. "They (culprits) cannot be pardoned and will not be forgiven either," Mubin vowed.

Earlier, emerging from the meeting with the premier around midnight, army chief General Moeen U Ahmed renewed the military's loyalty by saying, "Armed forces are always subservient to the government".

"It's a national crisis... we will have to overcome it," the army chief said.

Bangladesh has announced three days of national mourning from Friday, as the slain officers were buried with full state and military honours.