Updated

Japan asked the U.S. military not to fly its Japan-based HH-60 helicopters until it determines why one crashed at a U.S. base on the southern island of Okinawa, as the U.S. Air Force said Tuesday that it stopped searching for a missing crew member after finding remains.

Three of the helicopter's four crew members ejected from the aircraft and were in stable condition, the U.S. Air Force said in a statement. It said the human remains found near the crash site were not yet identified. Japan's defense minister had said Monday that information then available indicated all had survived.

Japan formally complained to the U.S. over the crash, which occurred at a time of intense local opposition to the U.S. Marine Corps' additional deployment of 12 MV-22 Osprey transport aircraft on Okinawa, where anti-U.S. military sentiment is a longstanding issue.

Dozens of opponents of the U.S. presence gathered Tuesday outside the Futenma base on Okinawa, chanting and raising fists and banners protesting the crash and demanding an end to the Osprey deployments.

"We have asked the U.S. not to fly the same aircraft until they find out the cause of the accident and take preventive steps," Defense Minister Itsunori Onodera told reporters Tuesday.

Chief Cabinet Secretary Yoshihide Suga said Japan had also asked Washington to postpone a planned additional deployment of a dozen Ospreys to Okinawa until the latest problem is resolved.

About half of the 50,000 U.S. troops in Japan are based on the island under a Japan-U.S. security pact, and many residents have complained about base-related crime, noise and accidents.

The HH-60 rescue helicopter, which belongs to Okinawa's Kadena Air Base, was on an unspecified training mission when it crashed at Camp Hansen.  Flying activities were suspended Tuesday at Kadena, for the sake of recovery operations, the Air Force statement said, with fixed-wing aircraft due to resume flights on Wednesday.

Local media said the crash revived memories of an accident in 2004, when a CH-53 helicopter from Marine Corps Air Station Futenma crashed into a university building, triggering a huge anti-base uproar although there were no civilian injuries and the crew survived.

"We knew it was going to happen sooner or later," said Kadena Mayor Hiroshi Toyama, referring to Monday's crash.