DAMASCUS, SYRIA, JUNE 18 -- Gunmen seized Charles Glass, an American television journalist and writer, along with the son of Lebanon's defense minister and their driver as they were traveling from Sidon to Beirut yesterday along a coastal highway in Lebanon policed by Syrian and Lebanese soldiers.

Glass, 36, the ninth American in captivity in Lebanon, is the first kidnaped there since January and the first westerner taken captive since Syria sent 7,000 troops to the Beirut area in February. His abduction coincides with growing tension between the United States and Iran over navigation in the Persian Gulf.

No claims of responsibility had been made by late today, more than 24 hours after Glass and Ali Osseiran, son of Defense Minister Adel Osseiran, a Shiite Moslem, were seized by three carloads of gunmen who intercepted their vehicle at a junction linking the coastal highway to the mainly Shiite suburbs near the southern entrance to Moslem west Beirut -- and only 500 yards from a Syrian military checkpoint, according to the Christian Voice of Lebanon radio.

The Iran-linked Hezbollah, or Party of God, which is believed responsible for most hostage-taking in Lebanon, last week bitterly criticized the Lebanese military establishment after the assassination of Prime Minister Rashid Karami. Karami, a close ally of Syria, was killed June 1 by a bomb planted in the Lebanese Army helicopter in which he was riding.

In Damascus, Shiite Amal militia leader Nabih Berri asked Syrian security officials to help find Glass. Ghazi Kanaan, the chief of Syrian military intelligence in Lebanon, was recalled to Damascus tonight, political sources said. A spokesman for ABC News, for whom Glass had worked, said Syrian authorities had promised to attempt to trace the American journalist.

State Department officials in Washington said the abduction may have been intended to draw the United States into negotiations for the release of Glass and other American hostages.

"We assume this is another terrorist attempt to manipulate the United States through our concern for our citizens," a department statement said.

Spokeswoman Phyllis Oakley said in response to a question that Glass might have been in technical violation of U.S. passport rules imposed in February to keep Americans out of Lebanon, The Associated Press reported. Oakley said there was no indication Glass had applied for an exception to the travel ban, which he would need in order to use his U.S. passport for travel there.

Glass had covered the Middle East for ABC for four years and gained prominence in June 1985 for his interviews with crew and passengers of a TWA jetliner hijacked to Beirut. He left ABC in March and was in Lebanon to work on a book, his British wife, Fiona, told United Press International. Fiona Glass and their five children live in London.

"He was there because he's writing a book about the Middle East -- he knows the area very well," Fiona Glass said. "And he is in fact of Arab extraction himself." UPI said Glass' grandmother was Lebanese.

Glass had returned to Beirut on May 25 after a two-week vacation with his family in London. He entered chaotic west Beirut last week despite warnings from friends to be cautious. He was generally reluctant to discuss his movements with colleagues and would drop out of sight for short periods.

When he failed to meet a number of appointments in the past 24 hours, however, people in close touch with him became concerned and began making inquiries. Glass usually stayed at the home of Hani Salam, a tycoon and Sunni Moslem adviser to President Amin Gemayel, in Doha, south of Beirut.

This week, Glass was visiting with the Osseirans, a prominent Lebanese family. Defense Minister Osseiran told journalists in Beirut that Glass and his son left their home outside Sidon, a port city south of Beirut, at 10 a.m. yesterday and had not been seen since. Their driver, Ali Suleiman, a former policeman, reportedly was armed only with a pistol.

Sarah Osseiran, wife of the defense minister, said, "Yesterday at breakfast Charlie was nervous. He said good-bye in a hurry. He said, 'I'll see you soon,' but did not disclose where he was going."

Salam, who provided Glass with a driver and guard when he was in west Beirut, said he was using a car of the Osseirans' yesterday. He said he was told that the three were intercepted about 4:15 p.m. as they approached Beirut's southern limits at Ouzai.

Salam, reached by telephone in Cannes, France, said he had been told that three cars with armed men blocked their vehicle and Glass was dragged out. When Ali Osseiran protested and tried to stop them, he too was taken, along with the driver, Salam said.

The State Department said the incident pointed out the extreme hazard of travel in Lebanon and added that it held the kidnapers responsible for the safety of their victims.

"While we are deeply concerned for the well-being of Mr. Glass, Mr. Osseiran and all the hostages, American and foreign, and extend our sympathy to their families and friends, we repeat that we will not yield to terrorist blackmail," said a spokesman for the State Department in Washington.

Glass was the only American journalist still active in Beirut. An exodus of foreign journalists, prompted by a wave of kidnapings in the past two years, has reduced the western press corps to a handful of people still willing to take the risk.

The tall, dark-haired correspondent, who has also worked for Newsweek and other U.S. and British publications, had said he considered himself immune to some of the occupational hazards of reporting in Lebanon because he knew the country so well and because of his large network of Lebanese friends.

Despite the dispatch of Syrian troops to Beirut on Feb. 22, a predicted crackdown on Islamic fundamentalists in Beirut's teeming southern suburbs has not happened. Syrian military officials have said any storming of the densely populated Shiite slums would be disastrous for the safety of foreign hostages believed to be held in the area.

There are now at least 24 foreigners being held hostage in Lebanon. They include nine Americans, two Britons, two West Germans and three Frenchmen.

In Damascus today, the head of Iran's Revolutionary Guards denied an account published in the Lebanese weekly Ash Shiraa this week that some U.S. hostages had been taken to Tehran. The Iranian described the accounts as "pure lies."