DUBAI, United Arab Emirates — An Iranian missile set fire to an American-owned supertanker Thursday in coastal waters near Kuwait's main oil-exporting terminal.
The missile attack increased tension in the northern Persian Gulf, already running high after two American strikes against Iranian patrol craft.
Although it could not be confirmed, Kuwaiti officials said they were convinced that the Iranians had fired a Silkworm anti-ship missile from the Faw Peninsula below Abadan, which they captured from Iraq in February, 1985.
In Washington, Pentagon spokesman Fred Hoffman said: "It appears to have been a Silkworm . . . emphasis on 'appears to be.' We don't have a final conclusion."
He added that there was "no way of telling what it was aimed at," or where it was fired from.
Smaller Missile Possible
Other sources suggested that the missile was smaller than a Silkworm and may have been fired from an Iranian gunboat.
The missile hit the 275,932-ton tanker Sungari at dawn about nine miles from the Al Ahmadi terminal. The explosion sent a column of flame into the air and caused a fire that took five hours to extinguish.
Although American-owned, the Sungari is registered in Liberia and is not entitled to a U.S. Navy escort. Since July, the Navy has been escorting Kuwaiti tankers re-registered in the United States. The most recent American convoy arrived in Kuwait on Tuesday, and its Navy escort left the area. No Navy ships were present during Thursday's attack.
Asked about the attack, President Reagan said, "Our policy is still we're going to defend ourselves if attacked."
'No Response Indicated'
Hoffman, in response to questions about possible U.S. retaliation, said: "There is no response indicated at this point. Our shipping has not been struck . . . and is not affected."
Rep. Les Aspin (D-Wis.), chairman of the House Armed Services Committee, said at a meeting with reporters that the Reagan Administration should consider eventual use of an economic blockade in the Persian Gulf that would include mining Iran's harbors and perhaps include Soviet participation.
The attack on the Sungari occurred several hours after Iraqi jets attacked an Iranian shuttle tanker, the Pegasus I, near Iran's main export terminal on Kharg Island. The 231,990-ton Pegasus I had already been hit once, last year, by Iraqi planes.
Iran warned that its attacks on Iraqi cities will continue despite worldwide reaction against Iran for a missile attack that killed 29 children Tuesday at an elementary school.
A Tehran radio broadcast said, "The preemptive attacks of the fighters of Islam will not cease so long as the evil acts of the Iraqi regime in attacking Iranian civilian targets, including mosques, schools and urban centers, continue."
Four 'Safe Cities'
The broadcast said there would be only four "safe cities" in Iraq--Najaf, Karbala, Kazima and Samara. The Shia Muslims who make up the majority of Iran's population regard these cities as holy places.
A spokesman for the Kuwaiti Defense Ministry said that "Kuwait holds Iran responsible for the attack on the tanker and calls on the international community, especially the (U.N.) Security Council, to quickly apply its Resolution 598,which calls for an end to the Iran-Iraq War."
The Security Council adopted the resolution unanimously on July 20. It calls for an immediate cease-fire and withdrawal of all troops from occupied territory. Iraq, which started the war in 1980, immediately agreed to accept the cease-fire, but Iran expressed reservations. A de facto cease-fire went into effect but lasted just six weeks.
The tiny emirate of Kuwait has become a prime target for Iranian retaliatory strikes largely because it provides financial assistance to Iraq and allows war materiel to pass through its ports en route to Iraq.