Thirteen American military experts were able to get near the Abu Sayyaf camp in Maluso, Basilan, where the terrorist group has been hiding its hostages for the past five months, a security official said.

The U.S. anti-terrorism experts went to Maluso town to evaluate the fighting skills of Filipino soldiers who were tasked with rescuing American missionary couple Martin and Gracia Burnham, and eight other Filipinos, said an official, who declined to be named.

When they came back to Zamboanga City's southern command headquarters, the American experts talked and allowed themselves to be photographed for the first time.

"It was a learning experience for both parties," said a Filipino military leader.

"We realised what the Filipino soldiers need in their job," said one American expert. Earlier, they refused to talk to reporters.

At least 24 U.S. experts from the Army and the Marines arrived in two batches in Zamboanga City late last month.