(CNN) -- At least 40 bodies -- all of them wearing uniforms identifying them as army officers -- have been found in a mass grave inside the headquarters of the Bangladesh Rifles paramilitary in the capital, Dhaka, authorities said Friday.

Bangladeshi army soldiers gather near the Bangladesh Rifles headquarters in Dhaka Thursday.

The discovery brings to at least 62 the number of army officers who have been found dead after mutinous paramilitary forces took dozens of superiors hostages at the Bangladesh Rifles (BDR) headquarters on Wednesday.

The Rifles laid down their arms after Prime Minister Sheikh Hasina agreed to grant them amnesty.

The bodies were found in a grave behind the mortuary building inside the BDR compound in the Pilkhana area of Dhaka, said Cmdr. Abdul Kalam Azad with the Rapid Action Battalion (RAB), an elite internal security team that is helping with the recovery effort.

"It's a bad scene," Azad said. "You can only see their legs. We're carrying away only as many as we can fit in ambulances. Then we're going to go look for more."

Earlier, 22 bodies had been recovered from the Buriganga River after the rebelling troops dumped them down a sewer during the standoff, authorities said.

The Rifles took their superiors -- all military men -- hostage Wednesday morning after a rebellion they said was spurred by years of their grievances not being addressed.

Discontent had been bubbling for years among the ranks of the BDR troops, a 65,000-strong paramilitary outfit primarily responsible for guarding the country's borders.  Watch how the paramilitary revolt spread Â»

The recruits complained their army superiors dismissed their appeals for more pay, subsidized food and opportunities to participate in U.N. peacekeeping operations.

Bangladesh and its South Asian neighbors contribute the most troops to such U.N. operations. And the pay is far greater than the meager salary the jawans -- as the BDR troops are called -- make.
Who offered amnesty? Who offered the Bangladesh Rifles amnesty? Where was a mass grave found? A mass grave was found with who in it? The rifles were given what by the PM? How many Bangladesh officers were found buried? How many officers were found dead? Who was found dead? How many officers were killed in this incident? When did the Bangladesh Rifles stop fighting back? How many offers were found dead? Who laid down arms?
Prime Minister Sheikh Hasina Prime Minister Sheikh Hasina inside the headquarters of the Bangladesh Rifles paramilitary in the capital, Dhaka, army officers amnesty. At at least 62 army officers at least 62 Wednesday. 62 The Rifles
question: Who offered amnesty?, answer: Prime Minister Sheikh Hasina | question: Who offered the Bangladesh Rifles amnesty?, answer: Prime Minister Sheikh Hasina | question: Where was a mass grave found?, answer: inside the headquarters of the Bangladesh Rifles paramilitary in the capital, Dhaka, | question: A mass grave was found with who in it?, answer: army officers | question: The rifles were given what by the PM?, answer: amnesty. | question: How many Bangladesh officers were found buried?, answer: At | question: How many officers were found dead?, answer: at least 62 | question: Who was found dead?, answer: army officers | question: How many officers were killed in this incident?, answer: at least 62 | question: When did the Bangladesh Rifles stop fighting back?, answer: Wednesday. | question: How many offers were found dead?, answer: 62 | question: Who laid down arms?, answer: The Rifles