MANAMA, BAHRAIN, JAN. 8 -- Iraq said its warplanes bombed an Iranian refinery today, which also marked the seventh day of a rare lull in attacks on Persian Gulf shipping.

Two Syrian envoys ended a tour that Arab diplomats called an effort to arrange talks between Iran and gulf Arab nations eager to end the Iraq-Iran war and related raids on commercial shipping. About 450 vessels have been attacked since the war began in September 1980.

President Hafez Assad of Syria, an old enemy of Saddam Hussein, the Iraqi president, has supported Iran in the war.

Defense Secretary Frank Carlucci, inspecting U.S. forces in the gulf, told reporters that the United States and its allies can handle any threat to their national-flag merchant ships in the waterway, adding that there are "no current plans" to extend U.S. Navy protection to ships of other flags.

He said the size and role of the 33-ship U.S. force in and near the gulf "are under continuing review."

Speaking on the helicopter carrier Okinawa to a news pool organized by the Pentagon, Carlucci said U.S. willingness to escort ships and respond to attacks prompted Syrian efforts to ease Iranian pressure.

"The main thing that is sending a signal is our own presence here and the kind of actions that we have been taking, making it clear to the Iranians that reckless adventurism -- piracy, if you will -- will not bear political dividends," he said.

The second U.S. Navy convoy of the year entered the gulf through the Strait of Hormuz at dawn today and was steaming toward Kuwait with two reflagged Kuwaiti tankers, a Navy spokesman said.

Iraq's official news agency said warplanes bombed "the extremely important refineries of Tabriz," 100 miles inside the northern border.

A dispatch from Iran's official news agency said Iraqi planes raided "a non-military area in Tabriz . . . causing property losses but no casualties."