Windows shattered but nobody was hurt at the embassy in San'a. Britain's foreign secretary said a bomb may have been flung onto embassy grounds. Authorities were investigating.
The new attack came as American military planes evacuated 22 of the 35 sailors injured in Thursday's blast to Germany for medical treatment.
Navy officials in the United States said explosives experts who examined the USS Cole's damaged hull have concluded that the blast came from an external source, bolstering the contention that it was a terrorist attack. The ship was refueling in Yemen at the time.
Western diplomats in Yemen said the explosion seemed to be the work of a well-organized group with good connections in the port of Aden who might have provided the bombers with some logistical support.
The diplomats, insisting on anonymity, said the boat used by the suicide bombers was similar to boats used by port authorities to guide vessels into port or facilitate ships with refueling.
Seven soldiers have been confirmed dead and the families of 10 who remain missing are being notified that they are presumed to have died, U.S. Navy spokeswoman Lt. Cmdr. Cate Mueller said in Washington. Efforts to recover their remains were continuing, she said.
Thursday's blast tore a hole 20 feet to 40 feet in diameter. U.S. officials say suicide bombers blew up a small boat next to the 9,100-ton destroyer.
The French Defense Ministry said Friday its army planes had taken 11 of the injured overnight to Bouffard military hospital in Djibouti, where six underwent surgery. Lt. Terrence Dudley, a U.S. Navy spokesman, said 22 others were evacuated Friday to Germany. Two, apparently less seriously hurt, remained in Aden.
In Germany, officials at the Ramstein Air Base said they were expecting bodies of the dead sailors to begin arriving later today and the injured late Friday or early Saturday. The injured were to be taken to the Landstuhl Regional Medical Center, a U.S. military facility.
Dudley said some of the injured USS Cole sailors were in serious condition and others were stable. He did not elaborate.
American investigators as well as U.S. Marines and soldiers filled Aden, bringing in equipment to search for clues beneath the water near the USS Cole. Sniffer dogs also were seen being brought to the area.
Dudley said investigators may keep working at the site another two days. The USS Cole, one of the world's most advanced warships, was left slightly tilted in Aden harbor.
"The ship took [in] some water and we are trying to dewater it. But, generally, it is seaworthy and we will tow it to the United States," said Dudley, of the Bahrain-based U.S. 5th Fleet.
The Cole is a $1 billion guided missile destroyer home-ported at Norfolk, Va. It was heading with a crew of about 350 to the Gulf for maritime intercept operations in support of the U.N. embargo against Iraq.
Anti-American sentiment has been running high in the Arab world, where protesters have been condemning the United States during demonstrations against Israel's actions in two weeks of deadly clashes in Jerusalem, elsewhere in Israel and in the Palestinian territories.
Yemen, an impoverished country on the tip of the Arabian Peninsula on the Red Sea, is known for its anarchic politics, streak of Islamic fundamentalism, and routine snatches of Western hostages who generally are exchanged unharmed for government pledges to provide basic services.
In Washington, President Clinton said Thursday that the USS Cole explosion appeared to be an act of terrorism, the worst against the U.S. military since the bombing of an Air Force barracks in Saudi Arabia in 1996 that killed 19 troops.
"We will find out who was responsible and hold them accountable," Clinton pledged.
He dispatched to Yemen investigative teams from the FBI, the State Department, and the Pentagon. Clinton also ordered a heightened state of alert for all U.S. military installations around the world.
No one has claimed responsibility, Defense Secretary William Cohen told a Pentagon news conference.
Yemeni officials privately rejected the accusations of a suicide attack, saying a joint investigation is needed to determine the cause of the blast.
Dudley would not say whether any Yemeni authorities were involved in the investigation.
"The investigation is being done by our team and is being conducted quickly and fairly," he said. "I can't go into the details of the status of the investigation."
Yemeni police officials said a number of people had been detained for questioning. The officials, speaking on condition of anonymity, did not say how many or if any were considered suspects.
Yemeni police and soldiers sealed off the port area, preventing ships and small boats from approaching the warship. Gen. Mohamed Saleh Gedrif, Aden security chief, refused to allow journalists into the port, saying the area is considered a closed security zone.
The explosion broke windows in homes and businesses along the Red Sea coast and overturned a car passing about 60 feet from the destroyer. It wasn't clear what happened to the occupants.
Yemen became a more frequent refueling stop for Navy ships following a December 1997 U.S. decision to open up contacts and cooperation with the country. Four years earlier, there had been small bombings outside the U.S. Embassy and at hotels where Americans were staying.
Islamic extremists have been active in Yemen. However, Yemeni Prime Minister Abdul-Karim al-Iryani said in March that the United States' most-wanted terror suspect, Osama bin Laden, at one time had "colleagues" in Yemen, but now "has no place in Yemen, no military camps."
The United States accuses bin Laden of organizing a militant network with followers across the Mideast, including Yemen, and says he masterminded 1998 bombings against the U.S. embassies in Kenya and Tanzania, which killed 224 people.
Yemen was also one of the countries where members of the Palestine Liberation Organization settled after losing a base in Lebanon. Few Palestinians remain in Yemen today.