IWO JIMA, Japan — A team of U.S. searchers looking for the remains of the Marine who filmed the famous flag raising over Iwo Jima say they've located two possible sites and recommend a larger group excavate them, officials said Wednesday.

"Our investigation has been very successful," U.S. Army Major Sean Stinchion told The Associated Press, the only civilian media with the search team that had been surveying and digging on the island for 10 days.

"We found two caves and tunnels. We will recommend a follow-up team be brought in to use heavy equipment," he said.

He said the team did not find the remains of sergeant William H. Genaust, who filmed the flag-raising nine days before he was killed during combat on the island.

"We are the initial investigation. We surveyed the hill. We will need to return to actually dig for specific remains," Stinchion said.

The seven-man team, including an anthropologist, focused mainly on surveying Hill 362 A, where Genaust was believed to have been killed.

It was the first U.S.-led search on Iwo Jima — one of the fiercest and most symbolic battlegrounds of World War II — in nearly 60 years.

The seven-member team arrived on Iwo Jima on June 17 and began slashing its way through thick, thorny brush on the island's interior in search of the area where Genaust is believed to have been killed.

A combat photographer with the 28th Marines, Genaust filmed the raising of the flag atop Iwo Jima's Mount Suribachi on Feb. 23, 1945, standing just feet away from AP photographer Joe Rosenthal as he took the photograph that won a Pulitzer Prize and came to symbolize the war in the Pacific.

Genaust, then 38, died nine days later when he was hit by machine-gun fire as he was helping fellow Marines secure a cave, said Johnnie Webb, a civilian official with the Joint POW/MIA Accounting Command.

Iwo Jima continues to be an open grave. Though most of the American dead were recovered in 1948, some 250 U.S. troops are still missing from the Iwo Jima campaign. Many were lost at sea. But many others died in caves or were buried by explosions.