MUSCAT, Oman (AP) _ A tanker carrying millions of gallons of oil exploded and caught fire in the Arabian Sea, leaving four sailors dead and 18 missing Monday.

The blast occurred Sunday as the Maltese-flagged Stolidi sailed about 250 miles east of the Omani island of Masirah, bound from Oman to South Korea, according to Lloyd's of London shipping intelligence unit.

Greece's Merchant Marine Ministry said the Stolidi was carrying a crew of six Greek officers and 31 Filipino sailors.

''Eighteen foreign sailors are missing and four foreign sailors are dead,'' it said. Nearby ships picked up the survivors, the ministry said.

Lloyd's, which monitors maritime traffic around the world, said rescue teams took survivors to Omani hospitals, but had no other details on the accident or the 267,039-ton vessel's condition.

Oman's coastline appeared to be under no immediate pollution threat because the explosion occurred far enough out to sea to let any spilled oil dissipate before reaching shore.

Persian Gulf-based shipping executives said radio shipping channels crackled early Monday with distress calls from merchant ships that rushed to help the blazing tanker.

The Stolidi sailed from Oman's main oil loading terminal, Mina al-Fahal, on Saturday after loading just under 20 million gallons of Omani crude, said the executives, who spoke on condition of anonymity. They said the tanker also took on oil from other gulf ports.

A spokesman for Silver Carriers of Athens, Greece, said his company managed the tanker. He said the owners were not Greek, but refused to identify them. He spoke on condition of anonymity.