ADEN, Yemen - Investigators found bomb-making equipment in an apartment near the port of Aden and believe two former occupants may have carried out the suicide bombing that killed 17 sailors aboard the USS Cole, security officials said Tuesday.
U.S. authorities would not comment directly on the disclosure. But the ambassador, Barbara Bodine, described the investigation as advancing ''a quantum leap.''
''We are very hopeful we are going to get to the bottom of this,'' she said.
Yemeni officials, who spoke on condition of anonymity, identified the missing men only as non-Yemeni Arabs. Other Yemeni officials said they were from neighboring Saudi Arabia.
Moments before the huge blast Thursday, two men were seen standing on the deck of a small vessel alongside the destroyer, U.S. authorities said. A 40-by-40-foot hole was blown into the Cole's hull and the attack ship disintegrated into ''confetti size'' pieces.
On Tuesday, divers and other crew members using metal-slicing torches and crowbars pulled six more bodies from the tangled bowels of the Cole. Officials initially said seven bodies were recovered Tuesday, but later corrected the figure. Six victims remain trapped near the blast site.
In Virginia, four of the more seriously wounded Cole sailors arrived at Norfolk Naval Station after a flight from Germany. Most of the 39 injured sailors had arrived in Virginia over the weekend, while two critically injured shipmates remain at the military's Landstuhl Regional Medical Center in western Germany.
Speaking about the two suspects, the Yemeni officials said the apartment was searched Monday, when Yemen reversed an earlier position and called the blast ''a premeditated criminal act.'' A senior Saudi intelligence official visited Aden on Monday, but no details of the meeting were made public.
The Yemeni officials would give no further information on the material found, but said the missing men arrived in Yemen four days before Thursday's attack.
Bodine declined to comment on details of the case or speculate on possible links to larger terrorist groups, including that of Afghan-based Saudi dissident Osama bin Laden. She stressed that the investigation would continue.
''We want this investigation to go further ... to see how far back we can walk this. And those kinds of investigations can sometimes take some time,'' she said.
The Yemeni find could be a key break on the first day of work for a joint FBI-Yemeni task force. The hunt, however, is already well under way.
So far, Yemeni security forces have interrogated hundreds of port workers and others, including the head of the company that services U.S. warships. Some fragments from the blast were shipped to the United States for analysis by the first FBI agents to arrive after the attack. That initial evidence arrived on U.S. shores Monday night.
There has been no credible claim of responsibility for the deadliest terrorist attack on the U.S. military since the 1996 bombing of an Air Force barracks in Saudi Arabia that killed 19.
Immediate suspicion fell on bin Laden, accused in the 1998 bombings of U.S. embassies in Kenya and Tanzania that killed 224 people. In retaliation, the United States fired dozens of Tomahawk cruise missiles at his suspected stronghold in eastern Afghanistan.
In his first statement since December 1998, bin Laden said Tuesday that another such attack would not kill him or deter his battle against the ''enemies of Islam.'' He made no direct reference to the Aden attack. Afghanistan's Taliban rulers on Monday denied bin Laden was involved, but also said Tuesday that he could not have issued a statement because all means of communications have been denied him.
FBI Director Louis Freeh transferred the investigation from Washington to the command of John O'Neill in the New York field office, which handled the East African embassy bombing cases. But U.S. officials denied this meant they could link the blast to bin Laden at this point.
The full FBI team is expected to swell to 100 agents. Seventy are already in Aden, and 30 others are waiting in Germany for accommodations to be arranged.
Many Yemenis have said they do not believe the attack was the result of a homegrown plot, and Tuesday's disclosures put the spotlight on Saudi Arabia. Bin Laden is a Saudi national of Yemeni heritage.
Border disputes have marred relations between Yemen and Saudi Arabia, but an agreement was signed in June to seek a solution. Yemen has long contested the Saudi claim to three Red Sea islands and parts of the Empty Quarter, a vast desert region with potentially lucrative oil deposits.
Aboard the stricken Cole, wreckage specialists fought their way through collapsed bulkheads and a maze of twisted metal to reach bodies. Above the oily harbor water, blowtorches cut slowly through the reinforced steel. Beneath them, in the cavern created by the blast, divers poked slowly through murky passages and fissures.
The divers - some of whom plucked victims from the doomed TWA 800 flight near Long Island in 1996 - carried tools to try to pry apart the metal trapping the bodies.
The bodies recovered Tuesday were found above and below the water line, said Rear Adm. Mark Fitzgerald, who is leading naval operations in the area. The cause of death: ''trauma from the blast,'' he said.
Five bodies were recovered last week and were flown back to the United States.
A memorial service for victims of the bombing is scheduled Wednesday at Norfolk Naval Station, the Cole's home port in Virginia. President Clinton and Defense Secretary William Cohen plan to attend.
Security worries in Aden have mounted as more American investigators arrive in a nation the State Department described as a ''haven'' for terrorists. Efforts are made to keep most personnel either on other U.S. warships just offshore or in a hotel guarded by Yemeni soldiers and U.S. Marines.
U.S. Navy officials say it could be weeks before the Cole can be raised onto a heavy lift ship and transported back to the United States for repairs.
Nearly a week after the blast, one Cole sailor said she still has difficulty absorbing the aftermath.
''The first time I got a chance to sleep for an hour or so ... I woke up and I forgot,'' said Lt. Ann Chamberlain, of Washington, D.C.. ''It's weird.''