The Japan Coast Guard is continuing to search for four Americans reported missing Sunday near the Okinawa prefectural island of Ishigaki after their yacht encountered battering winds and crushing waves from Typhoon Jangmi, a Japanese official said Monday.

The four men were sailing from Malaysia to Okinawa aboard the 66-foot yacht Jade Princess on Sunday, when they sent out a radio distress signal at 11:06 a.m., said Takamichi Higa, Japan Coast Guard spokesman in Naha.

Rescue planes spotted the Jade Princess’ emergency locator radio transmitter and debris believed to be part of the yacht about 38 miles northwest from where the initial distress signal originated, Higa said.

The Japan Coast Guard said it had received reports that the yacht may have been equipped with a rescue raft, Higa said.

"The raft has yet to be found," he said. "In finding the raft, we keep our hope, slim as it may be."

The identities of the missing passengers were unavailable Monday.

The men ultimately were headed to Yokohama in mainland Japan, where they planned to board a cruise ship, Higa said.

A U.S. Navy 7th Fleet spokesman, Chief Robert Garnand, said a Navy P-3 Orion from Kadena Air Base on Okinawa assisted in Monday’s search. He had no further information.

"None of that information has trickled back to us yet," he said.

The U.S. Coast Guard is monitoring the situation, but the search is being handled by Japan because the disappearance occurred in its territory, said Lee Putnam, a Coast Guard search and rescue specialist on Guam.

Two Japan Coast Guard rescue airplanes were dispatched to the area Sunday. Rough waters prevented patrol ships from immediately entering the area, Higa said.

The distress signal was transmitted from a point about 62 miles southwest of Ishigaki, Higa said.

Attempts to reach the men by the maritime telephone were unanswered, he said.

Winds registered at nearly 80 miles per hour by Sunday afternoon, according to the Okinawa Meteorological Observatory.

The typhoon lashed the Ishigaki area Saturday for about four hours before proceeding to Taiwan, where it stormed for about 12 hours, the observatory reported.

Higa said the yacht departed Sept. 21 from Malaysia.