MANAMA, BAHRAIN, DEC. 16 -- An Iranian gunboat peppered a Greek tanker with rocket-propelled grenades near the Strait of Hormuz today, and Iraq said its warplanes attacked three ships off Iran's coast within 13 hours.

Witnesses said the 29,990-ton World Produce had at least six holes punched in its stern.

Smoke poured from the holes, according to reporters who flew over the tanker in a helicopter. The owners in Athens said damage was minor. No injuries were reported, but three salvage tugboats spent two hours battling a blaze on the ship. The World Produce was on a regular run between the gulf and Asian ports.

The London-based Lloyd's Shipping Intelligence Unit and gulf-based marine executives confirmed Iraqi warplanes raided the Cypriot-flagged, 27,244-ton Mimi M at midnight and again today.

At least three crewmen were wounded in the missile attack off Iran's northern gulf port of Bushehr, they said. Lloyd's said the Mimi M, a bulk carrier, was hit again three hours later.

The Iraqi News Agency quoted a military spokesman as saying Iraqi warplanes hit another two vessels between midnight and 12:45 p.m. today. The report could not be independently confirmed.

The Iraqi spokesman said the attacks were part of Baghdad's strategy "to tear apart the arteries supplying oil revenue to the aggressor Iranian regime."

Shipping executives said Iran and Iraq appeared ready to intensify their so-called "tanker war" in the Persian Gulf.

The two nations have attacked more than 155 commercial vessels this year and more than 425 since the war began in September 1980.

At least 10 ships have been hit this month. Up to 22 crewmen were missing and believed killed in one Iraqi attack.

Shipping officials said Iraqi warplanes hit another tanker yesterday, the 289,776-ton Taftan, but Iraq did not claim the attack. The executives said the Taftan sustained only minor damage and continued its voyage.

One or more Iranian frigates were challenging several merchant vessels by radio in the southern Persian Gulf, demanding information on the ships' identities, cargos and destinations.

The Iranians also use the interceptions to select targets for their attacks.

Earlier yesterday, an Iranian frigate fired on the Greek tanker Ariadne off Dubai after warning it three times by radio that it would open fire unless it responded.