GENERAL SANTOS, Philippines — Japanese diplomats left the southern Philippines yesterday after four days of unsuccessfully trying to verify reports that two former soldiers from the Imperial Japanese Army had survived in the mountains since World War II.

Japanese officials cited security concerns in the region, which is notorious for Muslim guerrilla attacks and criminal gangs. But officials said efforts to arrange a meeting with the mystery men would continue from Japan's embassy.

"The mediator said that he will inform the embassy about the date and timing of the interview at a later date," Akio Egawa, the embassy's deputy chief, said in General Santos. He said the Japanese trader who first reported the case wanted the meeting held "in a more quiet situation."

Egawa said one reason the Japanese diplomats were leaving was security worries. Citing the presence of about 100 Japanese journalists on Mindanao island, he said, "If some journalists go into the mountains, that will be dangerous."

Egawa evaded questions about whether officials thought the mediator — a longtime resident of the Philippines — was trustworthy. Kyodo news agency, citing an unidentified official, said Japan had concluded the trader wasn't reliable.

In Japan, Chief Cabinet Secretary Hiroyuki Hosoda said attempts to arrange a face-to-face meeting with the purported old soldiers would continue despite suspicions the tale is a hoax.

Japanese journalists, who rushed to the area 600 miles south of Manila last week, have been raising doubts about the story, including speculation that the Japanese trader — who has not surfaced publicly — was part of an elaborate scam.

Japanese media also have reported that unidentified armed groups have demanded or received ransom for the men amounting to about $250,000. Egawa said the Japanese government was unaware of any ransom payments or demands.

The story about the two men surfaced last week, saying they became separated from their unit six decades ago and were afraid to return to Japan for fear of being court-martialed.

The Philippines, then a U.S. colony, was a major battleground in the Pacific. A few Japanese holdouts on its islands surrendered as late as 1948, three years after the war's end.

Then in March 1974, intelligence officer 2nd Lt. Hiroo Onoda came out of hiding on northern Lubang island. He had refused to give up until the Japanese government flew in his former commander to formally inform him the war was over.

Associated Press writer Kenji Hall in Tokyo contributed to this report.