Iraq said its ground forces recaptured part of the Majnoon Islands in a "heroic thrust" on Iranian strongholds yesterday. Iran said the Iraqi offensive on the oil-rich region was repelled.

Iraqi President Saddam Hussein, in a speech on the 65th anniversary of the creation of his nation's armed forces, warned Iranian leaders of a "major catastrophe" if Iraqi territory is invaded, Radio Baghdad reported, according to The Associated Press.

An Iranian military communique, carried by Iran's official Islamic Republic News Agency and monitored in Cyprus, said Iraqi attackers suffered hundreds of casualties "in this desperate attempt" to retake the islands in the 926-square-mile Hawizah marshes.

The military activity could not be verified independently. Reporters and neutral observers are seldom allowed to visit the front line.

The two countries have been engaged in a bloody and inconclusive border war on the northern flank of the Persian Gulf since September 1980.

In other developments, a Maltese tanker was blazing in the Persian Gulf 24 hours after being hit by an Iraqi missile, shipping sources said.

In Kuwait, the Defense Ministry anounced that a top Soviet military team led by the deputy defense minister, Gen. Vladimir Govorov, will arrive Saturday for an official six-day visit.