DUBAI, UNITED ARAB EMIRATES, SEPT. 12 -- United Nations Secretary General Javier Perez de Cuellar held extensive discussions today with Iranian officials, apparently receiving Tehran's first detailed response to a Security Council call for an end to the long-running Persian Gulf war.

Tehran radio reported that Perez de Cuellar met for several hours with Foreign Minister Ali Akbar Velayati and then met Prime Minister Mir Hossein Mousavi. Few details of the talks were available, although Iranian accounts of the meeting suggested that Tehran adhered to its position that Iraq must be branded the aggressor in the war as part of any cease-fire.

Tehran radio said, "Any move by international bodies is serious to us only when it leads to justice being done," an apparent reference to persistent Iranian demands that Iraq formally be identified as having started the war.

Iran's news agency IRNA later said that Mousavi thanked Perez de Cuellar for his "positive stance on the need to identify the aggressor party in the conflict."

A U.N. spokesman in New York was quoted as describing the meetings as "cordial and very detailed."

The secretary general's mission has assumed increased significance in light of a surge in attacks on shipping in the Persian Gulf and the buildup in the region of western naval forces sent to protect American-, British- and French-flagged vessels. Warships, including mine sweepers, from other European nations also are on their way to the gulf.

Iraq and Iran accused each other of continuing artillery barrages, despite a tacit agreement to respect Perez de Cuellar's request for a break in hostilities during his mission.

Baghdad said Tehran had shelled eight cities and towns in Iraq during the past 48 hours, and had done some damage after the U.N. chief's arrival in the region. It said 36 persons had been killed and scores wounded in the bombardments.

But a spokesman in Tehran said the Iraqi report was "pure fabrication," IRNA reported. Iran had "halted" reprisal attacks Thursday, the spokesman said, out of respect for the U.N. secretary general's visit.

Iran said Iraqi shelling killed or wounded 13 Iranian civilians.

There were no reports from either side of attacks on shipping in the gulf.

Kuwaiti tankers reregistered under the U.S. and British flags sailed south through the gulf today, according to reports from Kuwait. The supertanker Turnbridge, escorted by the British warship Andromeda, reportedly was near the end of its voyage through gulf waters, while two reflagged U.S. vessels began their outward journey from Kuwait under Navy escort.

Almost a dozen vessels had been reported hit by Iraqi air strikes or Iranian naval attacks during the three weeks leading up to Perez de Cuellar's mission. It was one of the most intense periods of attacks against shipping in the seven years Iran and Iraq have been at war.

It was primarily the so-called "tanker war" in the gulf that led to the United Nations Security Council resolution that has brought Perez de Cuellar to the gulf region. The resolution, passed in late July, calls on the two countries to observe a cease-fire, withdraw to internationally recognized boundaries and exchange prisoners.

Several dozen warships from the United States, Britain, France and the Soviet Union have assembled in the gulf in recent weeks, one of the largest gatherings of naval firepower since the end of World War II. {Egypt's official Middle East News Agency reported that three Soviet warships -- a mine sweeper, a submarine hunter and a support vessel -- sailed through the Suez Canal on their way to the gulf, news agencies said.}

Iraq has said it will accept the U.N. resolution if Iran also adheres to it fully. Tehran, for its part, has insisted that it is ready to discuss the measure, but only if the United Nations labels Iraq as the aggressor in the war.

Arab states have rallied behind the Iraqi position in recent weeks, calling on Iran to honor the cease-fire demand. Libya, a long-time ally of Tehran, joined the appeal after the Libyan foreign minister visited Iraq this week. Today, members of the Gulf Cooperation Council, meeting in Jeddah, Saudi Arabia, underscored the call for a cease-fire and condemned Iranian missile attacks against Kuwait this past week.

Members of the council are Saudi Arabia, Kuwait, Bahrain, Qatar, the United Arab Emirates and Oman.

Almost all Arab states except Syria have lined up against Iran on the cease-fire issue, and there is considerable pressure being placed on Damascus to follow suit. Syria now remains Iran's only major friend in the Arab world.

Perez de Cuellar is expected to meet Sunday with other top Iranian officials and then go to Baghdad Monday to begin talks with the Iraqi leadership. He is expected to return to New York toward the middle of next week to report to the Security Council on his mission.