DUBAI, UNITED ARAB EMIRATES, SEPT. 3 -- Iran and Iraq continued attacks on ships in the Persian Gulf today, as the U.S. Navy began escorting a new convoy of Kuwaiti tankers and the first deaths in the renewed "tanker war" were confirmed.

Iranian Revolutionary Guards ambushed a Japanese oil tanker with rocket-propelled grenades and fired bazookas at an Italian freighter overnight, while Iraq announced that it had bombed a tanker and oil rigs off Iran's coast.

There also were sharp reminders today that those who are at most risk in the six-day-old flareup in fighting belong to an underclass of sailors, mostly from impoverished parts of South and Southeast Asia. The first fatalities in the fighting were a Sri Lankan and a Filipino sailor whose small supply ship was sunk Wednesday by Iraqi jets, the ship's operator said. The planes struck the vessel during an attack on Iran's Kharg Island oil terminal, according to the shipping company, based in the emirate of Sharjah.

{In Washington, Pentagon spokesman Robert Sims confirmed that a new convoy of reflagged tankers left Kuwait Thursday, heading southward out through the gulf. Sims said the guided-missile cruiser USS Reeves and guided-missile frigate USS Hawes were escorting the Gas Queen and Gas Princess, 46,000-ton liquefied natural gas carriers, and the 290,000-ton supertanker Townsend. "It's the kind of routine escort that we said we were going to have when we began" the gulf reflagging and escort operation, Sims said.}

Most of the Indian crew from a ship attacked by Iran Monday quit the vessel in port here to fly home rather than sail back into the gulf.

Today's attack by Iranian Revolutionary Guards on the Japanese tanker Nisshin Maru appeared to be a mistake, as the ship was carrying Iranian crude for export. The guards' speedboats rushed the tanker off the coast near here and fired three rocket-propelled grenades into the hull, a shipping agency here said. Iranian commandos also struck an Italian container carrier, the Jolly Rubino, in the northern gulf.

Iran denied that it attacked the Japanese tanker. "The fact that {it} was carrying Iranian oil is sufficient to refute the . . . claim" that it was an Iranian attack, Tehran radio said.

{In Rome, the Iranian Embassy told the Italian government that Iran "categorically denies" carrying out the attack on the Italian ship, United Press International reported.}

Signs were emerging that the ship attacks by Iran and Iraq might adversely affect traffic levels in the gulf, through which about 17 percent of the world's energy resources flow. Today, in reaction to two attacks this week involving Japanese crews, Japanese shippers suspended voyages into the gulf by Japanese-flagged ships for two days, and Lloyd's of London increased insurance rates for gulf ships by 50 percent "in the light of recent incidents."

Traffic in the gulf bound for Japan is heavy, carrying more than half of that country's oil imports. Shipping agencies said a number of Japanese tankers had been halted just outside the gulf's entrance.

Today's confirmation that a Filipino and a Sri Lankan had died Tuesday underscored that it is mostly Asian men, who have fled poverty and unemployment at home, who face the bombs and bullets of Iran and Iraq. The last reported war casualties in the region were four Indians, a Korean and a Briton whose supply boat was sunk by a mine last month off the United Arab Emirates' port of Fujayrah, just outside the gulf.

According to descriptions of Iranian attacks this week, crew quarters of ships are generally targeted. That is where Iranian attackers of the Jolly Rubino, the Italian vessel hit last night, were aiming their bazookas, the ship's first engineer told United Press International today. "It was just for the fun of killing people," Donaldo Galioni said in a shore-to-ship interview. "It was a very, very ugly experience."

In Dubai, the plight of the gulf's Asian sailors is difficult for a visitor to see. While Indians, Pakistanis, Sri Lankans and Filipinos make up the dominant work force in stores and hotels here, the sailors who help keep Dubai's trading economy running are mostly confined to their ships and the port, which are closed to journalists.

But this week's story of an Arab-owned merchant ship with an Indian crew has shown that the Asian men from the slums of Bombay, Madras or Manila who sign on to crew ships risk becoming unsuspecting victims of the gulf war. The ship, the Jebel Ali, was sailing from the United States to Kuwait Monday when it became the first target of Iran's retaliation for renewed Iraqi air strikes on its ships and oil facilities.

After 3 a.m., as most of the ship's Indian sailors slept, Iranian motor launches roared out of the darkness to rake the ship with machine-gun fire and blast two holes in its side with rocket-propelled grenades. The crew of about 30 was unhurt but terrified.

After arriving in Dubai for repairs, crew members visited Indian Consul General Arun Kumar, asking to be sent home. "They had been hired in Bombay two months ago, and nobody had told them they would be sailing into a dangerous area," Kumar explained.

Kumar said the labor contractor who hired sailors for the shipowners told them that "they won't be sailing into the Iranian exclusion zone -- so everything would fine. They pictured these waters as places where you might go yachting or wind surfing."

An Indian journalist based here said the shipowners knew of a particular risk to the Jebel Ali: Iranian Revolutionary Guards had boarded the vessel in April as it was leaving the gulf.

Noting the ship's Arab ownership, the Iranians had advised that Indian crew not to sail on it in the future. Most of the crew subsequently quit and was replaced in Bombay.

Kumar said the company had added no war-risk bonuses to the sailors' basic salaries of $160 per month. And, according to Indian journalists here, when crew members asked to be flown home, the company at first demanded $450 in reimbursement for their two months of room and board on the ship -- even though the men had been paid only $320 for two months' work.

Negotiators for the labor contractor, Mackinnon Mackenzie, softened their stance today, agreeing to fly home the 15 sailors and nine officers who wanted to return. "It's a very fair agreement," said Kumar. "The replacement crew to be brought up from Bombay will be told clearly what the dangers are."

Several Indian sailors, interviewed outside Dubai's port, said the problems of the Jebel Ali's crew were typical. They regarded their own jobs, manning supply ships that service oil rigs and tankers, as much better work. "Their situation is very bad," said one sailor. "The ships are too hot, with no comfort."

An Indian journalist noted that few sailors from ships in port are seen in the city. "They are given little leave time and their salaries give them really nothing to spend," he said.

The troubles of Asian seamen speak even more loudly, though, of the economic desperation of their home cities. The attack on the Jebel Ali may have frightened its crew into going home, but Indians here say they will be replaced easily.

"In Bombay, men will come, even if they know about the war, because they have no work there," a sailor said. "Even {$160} a month can give life."