DUBAI, UNITED ARAB EMIRATES, AUG. 29 -- Iraqi warplanes resumed attacks on Iranian oil and shipping facilities in the Persian Gulf today, setting an Iranian oil tanker ablaze, shattering a tacit six-week truce in the naval war and drawing the promise of a "tooth-crushing response" from Iran.

The Iraqi attacks were the first on Iran's offshore oil installations since a July 20 United Nations Security Council call for a cease-fire in the seven-year-old Iran-Iraq war and the start of U.S. Navy escorting of reflagged Kuwaiti oil tankers at about the same time.

Iran has repeatedly vowed that it would retaliate against the oil installations of Kuwait, which is an ally of Iraq, and other friends of Baghdad if Iraq resumes the so-called "tanker war." The United States and other countries are known to have pressured Iraq in the past not to resume attacks on shipping. The day's events, many analysts here said, heighten the prospects for a resumption of the war at sea and threaten to draw in the American naval forces that are here in growing numbers.

Iraq started the tanker war in 1984 as a way to shut off Iranian oil exports that are used to finance Iran's war effort. But Iran has used the lull in the tanker war to increase its oil exports safely.

An Iraqi military communique said its jets had struck Iran's oil terminal at Lavan Island and an offshore oil platform in the Rakhsh oil field, both in the southern gulf. Baghdad also claimed to have hit, in the northern gulf, the Iranian military base on Farsi Island and a "large maritime target," standard Iraqi terminology for a tanker. Iraqi warplanes left all targets "with explosions erupting from them," the communique said.

Shipping sources in Dubai reported a separate raid on Iran's Sirri Island, an oil terminal about 65 miles northwest of here. They said an oil-loading facility and a 236,807-ton Iranian supertanker had been hit, and that the tanker continued to burn hours after the bombing. The Iraqi communique did not mention this attack.

The Iraqi communique said Iraq had struck in legitimate self-defense, given that Iran had failed to accept the U.N. Security Council resolution. In a speech on Baghdad radio, Iraqi President Saddam Hussein promised to continue the attacks on Iran's seaborne economic lifelines. "From now on, we will strike {Iran} at sea," he said.

During the de facto cease-fire, the United States had pushed for a formal truce under United Nations auspices. Over recent weeks, Iran has repeated that it would not strike gulf commerce or U.S. forces unless its own shipping was attacked. But Tehran vowed to retaliate against attacks on its commerce by striking vessels of Iraq's Arab neighbors, including Kuwaiti ships, 11 of which are being protected by the U.S. Navy.

Iran's official IRNA news agency said today's attack "reveals that the Baghdad regime does not abide by the international initiatives to return security to the region. {Iraq} will be solely responsible for the dire consequences of retaliatory attacks." The agency added that Iraq was trying to "fuel the fire of war." Quoting a spokesman for Iran's War Information Headquarters, the agency said Iran would deal "a tooth-crushing response to the Iraqi regime's attacks."

Before the Iranian statement, analysts in the region worried of a widespread flare-up in fighting. "No one can read the Iranians' minds, but we certainly have to expect that they will strike back," said a European shipping executive.

The threat of Iranian retaliation, with the risk that U.S. forces could become involved in the fighting, was one reason Washington has pressed Iraq to avoid striking Iranian maritime targets while efforts continued to get Tehran to abide by the U.N. Security Council call for a cease-fire.

{In Washington, the State Department said the United States had been watching the slow reescalation of hostilities in the gulf since the U.N. Security Council cease-fire resolution, but stopped short of condemning the attacks.

{"Recognizing the volatile situation in the gulf, we have counseled restraint on all sides while seeking an end to the war, not just tension in the gulf," the statement said.

{However, an administration official expressed some irritation at the Iraqi action. He said it would be "unhelpful" to U.S. diplomatic efforts to gain international support for a proposed U.N. Security Council arms embargo on Iran for its refusal to accept a cease-fire in the war.}

Iranian diplomats have said in recent days that Iran does not fully accept the resolution but does not officially reject it, either. Iraqi diplomats in Washington and Baghdad view the Iranian position as a rejection of the cease-fire demand.

The air strikes follow by one day a statement by Iraq's ambassador to Washington that Iraq would resume shortly its attacks on Iranian ships because it had lost patience with Iran's refusal to accept the U.N. resolution. "Our strategy is to continue to hit their ships until they accept the Security Council resolution," Ambassador Nizar Hamdoon said.

Iran also has continued to launch ground attacks against Iraq during the lull in the tanker war, and gulf observers, quoted by United Press International, said today's attacks seemed to indicate that Iraq was unwilling to accept the tacit cease-fire in the tanker war without a corresponding let-up in the ground war.

"The Iraqis seem to want to stir the pot," a western diplomat said. "They got tired of waiting for the Iranians and decided to up the stakes."

Today's attack surprised some political analysts here. They noted that last week Arab League members, including Iraq, had demanded that Iran comply with the Security Council resolution.

But, in his speech, Hussein vowed that Iraq will "destroy all the economic arteries that finance their military aggression." During the lull in the shipping war, Iran has increased its exports, according to some reports, earning up to $25 million per day.

There were few details on today's attacks. Iraq said it struck with "tens of planes," heavily damaging the oil facilities at Rakhsh and Lavan Island. It also claimed to have hit Farsi Island, which reportedly serves as a base for Iranian Revolutionary Guards to make guerrilla-style strikes against ships and to plant mines at sea.

Shipping sources here said more than one plane attacked the oil transfer anchorage at Sirri Island. They said the planes damaged the Alvand, a tanker owned by the Iranian state shipping company that has been shuttling Iranian oil from the northern gulf.

Since Iraqi air attacks have disrupted commerical traffic at Iran's main oil-loading terminal on Kharg Island in the north, Iran has used vessels such as the Alvand to shuttle oil down its coast to loading points in the south for transfer to vessels that carry it to overseas customers.

Shipping sources here had no news of movements today by American forces guarding the 11 Kuwaiti tankers reregistered under the American flag. They said it was believed that the amphibious assault ship USS Guadalcanal was in the southern gulf, not far from Dubai. Three Kuwaiti tankers were reported to be ready to leave Kuwait under U.S. Navy escort, while another convoy stood outside the southern entrance to the gulf.