TEHRAN, AUG. 16 -- The speaker of Iran's Parliament declared today that Iran has a factory "that could produce mines like seeds" to block Persian Gulf shipping, as the USS Guadalcanal reportedly arrived in the gulf with a complement of sophisticated mine-sweeping helicopters.

Speaker Ali Akbar Hashemi Rafsanjani, in remarks reported by the official IRNA news agency, warned that if Iraq should attack Iranian oil tankers and interrupt Iranian oil shipments out of the gulf, Iran would retaliate by disrupting all oil exports from the region, "even through pipelines."

The warnings, implying widespread mining of the gulf and attacks on Iraqi and Saudi Arabian pipelines, came in apparent response to reports from Baghdad that Iraqi President Saddam Hussein had said he reserved the right to strike Iranian warships and oil tankers as an act of legitimate defense designed to cripple Iran's economy.

Iraq sent warplanes deep into Iranian territory today, bombing two oil fields in Ahvaz in southwest Iran, according to a military communique from Baghdad.

The threats and counterthreats underlined the dangers of what is seen by diplomatic observers here as a particularly critical moment in the Persian Gulf crisis.

Although Iran seeks to avoid a confrontation, they said, renewed Iraqi air strikes on Iranian shipping, unauthorized raids by Revolutionary Guards or miscalculation could lead to hostilities involving the U.S. naval forces deployed in the gulf.

The amphibious assault ship USS Guadalcanal had been making its way to the gulf from the Indian Ocean island of Diego Garcia, where it had picked up eight mine-sweeping Sea Stallion helicopters. A British television journalist, Brent Sadler, on board a chartered vessel, said he spotted the U.S. ship 30 miles off Bahrain.

Sadler told the Reuter news agency that helicopter gunships and some of the mine-sweeping helicopters were circling the warship, flying less than 50 feet above the water in what appeared to be a search for mines.

Mine-sweeping helicopters set off mines by dragging sleds on the water at high speed in crisscross patterns. The sleds, which are roughly 15 feet by 20 feet, explode mines by hitting them.

The sleds also detonate underwater mines that are triggered either magnetically or acoustically.

The reported arrival of the Guadalcanal and the Sea Stallions means that the U.S. Navy probably is planning to include the mine-damaged supertanker Bridgeton in its next convoy out of the gulf, according to shipping sources in Kuwait.

They said departure of the convoy is imminent.

The 401,382-ton Bridgeton, the largest Kuwaiti vessel flying the U.S. flag, was holed by a mine July 24 during the first U.S.-escorted convoy to Kuwait. Shipping officials said the Bridgeton, temporarily patched up and partially loaded with oil, was kept in Kuwait pending arrival of the mine-sweeping Sea Stallions.

Smaller vessels, such as the Gas Prince, which was escorted in and out of the gulf, and the three ships that arrived in Kuwait under U.S. escort last week, can vary their routes in gulf waters.

But the supertanker Bridgeton, because of its deep draft, must remain in the main shipping channel off Iran's Farsi Island, where it hit the mine.

Farsi Island is believed to be a naval base for Iranian Revolutionary Guards. It is one of the bases from which the mining of gulf waters allegedly has been conducted. Western nations, including the United States, believe that Iran has been behind the mining of the Persian Gulf and the Gulf of Oman.

Two mines were detonated today in the Gulf of Oman by United Arab Emirates Army sharpshooters. A small commercial supply ship, the Anita, sank within seconds of hitting a mine off the UAE port of Fujayrah yesterday. At least six other mines reportedly have been found in that area during the past week.

The tough comments by Rafsanjani appeared to be part of an Iranian campaign to prevent the resumption of Iraqi air attacks on Iranian shipping or the escalation of the gulf crisis into a large-scale conflict that would halt oil shipments through the waterway. Iran is heavily dependent on oil exports through the gulf to finance its seven-year-old war with Iraq, diplomatic sources here pointed out.

As part of the campaign, Foreign Minister Ali Akbar Velayati visited Oman yesterday for talks with the Omani ruler, Sultan Qaboos. Velayati also sent messages to the Turkish and Japanese governments. At the same time, Deputy Foreign Minister Hussein Sheikholeslam visited Libya and Algeria.

Rafsanjani, Ayatollah Ruhollah Khomeini's representative on the Supreme Defense Council, which directs Iran's war effort, avoided taking responsibility for the mines that have been sown in the Persian Gulf and the Gulf of Oman, but his remarks were seen as a clear indication that such mine laying is part of the Iranian arsenal.

"We have a mine-producing factory that could produce mines like seeds," he said.

Rafsanjani also avoided taking responsibility for the explosion yesterday at the Juaymah natural gas plant in Saudi Arabia. But he said the Iranian leadership considers the explosion to be "an invisible aid."

Exports at the Saudi plant returned to normal today after a 24-hour interruption, Reuter reported. "Ships are back on berth" at the plant's offshore terminal, the agency quoted an Arabian-American Oil Co. official as saying.

As Rafsanjani did with the threat of mining, he appeared to be drawing attention to the weapons at Iran's command if Iraqi air strikes resume against Iranian-leased tankers in the gulf. He warned indirectly of sabotage against Saudi or Iraqi pipelines and other facilities in Saudi Arabia and Kuwait if these nations fail to prevent Iraq from attacking Iranian ships.

"If an incident happens in the Persian Gulf that halts oil exports from the region," he said, "regional oil will not be exported even through pipelines."

Iraq and Saudi Arabia export substantial quantities of oil through pipelines.

In addition, Kuwait and Saudi Arabia have offered facilities for export of Iraqi oil, and both nations are heavy contributors to the Iraqi war effort. "We have said that if Iraq stops its attacks in the Persian Gulf, we will ignore these issues," Rafsanjani said. Correspondent Loren Jenkins contributed to this report from Kuwait.