MANILA, March 14 -- After an earlier denial by the U.S. embassy in the Philippines, Manila says U.S. personnel were indeed involved in Oplan Exodus, the botched police operation in the town of Mamasapano, province of Maguindanao in Southern Philippines on Jan. 25.

A report released Thursday by the Board of Inquiry (BOI) of the Philippine National Police (PNP) confirmed that there were six Americans at the command center of the PNP's elite Special Action Force (SAF), hours before police commandos swooped down on the lair of wanted Malaysian terrorist Zulkifli bin Hir, alias "Marwan, " and his Filipino sidekick, Basit Usman.

In the pre-dawn operation, Marwan was killed while Usman escaped. But in the ensuing gun battle, 44 SAF troops, 14 combatants of the Moro Islamic Liberation Front (MILF) and five civilians were killed.

The BOI, which was tasked to investigate the encounter, said the information about the presence of the Americans at the SAF command post was provided by Police Superintendent Michael John Mangahis, a senior SAF official, who was also involved in the daring police mission.

"Mangahis revealed that six American nationals were at the TCP (tactical command post) in Shariff Aguak starting on the eve of the operations to provide real-time information to the SAF troops, " the report said.

It said in the retrieval operations, U.S. forces also helped in the medical evacuation of the wounded SAF commandos.

Police General Getulio Napenas, the relieved SAF commander, also told the board that he handed Marwan's left index finger, which the SAF troopers cut off for DNA samples, to two officials of the Federal Bureau of Investigation (FBI) in General Santos City three days after the police operation.

Later the FBI confirmed that through their preliminary DNA testing, the finger was from the slain terrorist.

Quoting the sworn statement of Napenas, the board said the PNP' s "U.S. counterparts had been providing reliable information" about Marwan and Usman.

Napenas said the information given by the U.S. authorities "was considered in covert operations against the high-value targets."

In its reaction to the BOI report, the Philippine Department of Foreign Affairs (DFA) said it checked reports of U.S. involvement in the SAF operation with the U.S. embassy and the embassy denied the U.S. involvement.

An embassy official, however, admitted that U.S. troops helped evacuate casualties in the Mamasapano raid but that the operation was "planned and executed by Philippine authorities."

The Philippines and the U.S. are long-time allies and have signed military cooperation agreements that include the Mutual Defense Treaty and the Visiting Forces Agreement both of which are still in effect.

As an ally, the Philippines has allowed the U.S. to have some troops in the Southern Philippines as part of U.S. war on terror. Until last month, the U.S. had a unit of about 500 to 600 special force soldiers in southern Philippines that trained local troops to fight Islamic militants.

Earlier, militant groups assailed the Aquino government for allowing the Americans to get involved in a purely domestic police operation.

In a statement, Roger Soluta, secretary general of the militant group Kilusang Mayo Uno (KMU) or May One Movement, said the involvement of the U.S. in the Mamasapano incident "exposed the dark truth behind the much-hyped U.S. war on terror."

Soluta said Malacanang, the presidential palace, was playing up the so-called war on terror of the U.S. "to cover up the fact that the operation violated the Philippines' sovereignty and was designed without consideration for Filipinos' lives."

"The U.S. is guilty not only of lying about its role in the Mamasapano operation and of trying to elude accountability for the operation. It violated the Philippines' sovereignty and killed many Filipinos, including civilians," Soluta said.

Soluta said that the U.S. "war on terror" has reinforced, rather than changed, the unequal relations between the U.S. and countries such as the Philippines, which allows Filipino troops to be used as "cannon fodders and considers Filipino civilian casualties as mere collateral damage."

Some Philippine lawmakers also inquired whether the U.S. military had played a leading role in the Jan. 25 operation.

Senate President Franklin Drilon, a strong ally of President Aquino, was one of at least five senators to have raised questions about U.S. involvement in Operation Exodus.

Under the terms of an anti-terrorism training deployment, the U. S. is not permitted to engage in combat in the Philippines.

The BOI also found Aquino as having broken the PNP chain of command by giving full authority to former PNP Director General Alan Purisima, his bosom friend, in the implementation of Oplan Exodus.

The report said Purisima, who has been suspended after graft charges were filed against him, had no authority to supervise the SAF operation.