It was a scene that had become familiar to Americans in cities around the world in recent years: tearful relatives milling by the buses, haggard diplomats issuing orders through walkie-talkies and helping load hastily packed bags, heavily armed security personnel patrolling the embassy grounds.

But this morning's evacuation from the Lebanese capital was of Soviet diplomatic staff and dependents, departing for Damascus in the face of threats by an Islamic fundamentalist group to blow up the embassy by this afternoon and in the aftermath of the abduction of four of their number and slaying of one of them by the group.

"We have had many evacuations," said a Soviet diplomat who is remaining behind, "but never one like this. I have spent 15 years altogether in Lebanon. I have seen everything here," he observed as he took pictures of acquaintances with a Japanese-made camera.

Also remaining behind is Tatiana Svirsky, wife of abducted embassy physician Nikolai Svirsky, who gathered with her countrymen in the shaded gateway to the embassy this morning and stared vacantly at the commotion around her. Dr. Svirsky, press attache Oleg Spirine, commercial section representative Valery Mirikov and consular secretary Arkady Katkov were kidnaped in two separate actions Monday, and Katkov's body was found Wednesday.

"If I had no hope, I would not be staying," Tatiana Svirsky said shyly, lowering her eyes. Most other women were ordered out by the Kremlin along with other nonessential diplomatic staff.

Asked whether she was angry at the Lebanese, she snapped, "Yes, I feel bitter." Then she looked away and wept.

Between 70 and 100 Soviet residents and diplomats with stuffed travel bags milled around the embassy grounds off the Corniche Mazraa boulevard as Soviet-made T54 tanks with their guns pointing outward guarded side streets. Charge d'Affaires Yuri Souslikov supervised the evacuation with officials of the Druze Progressive Socialist Party, whom Soviet officials refer to as "our friends in Lebanon."

Other embassy officials paced nervously with walkie-talkies and some hastened to dump hurriedly packed cases and shopping bags onto two trucks full of suitcases and cardboard boxes. One diplomat carried a white nylon bag with cartons of American cigarettes and Lebanese apples.

Souslikov, wearing a light gray suit, chatted with a group of women. He said some of the men going to the Syrian capital would be coming back later. "Some of my staff I don't need, like our Orientalist for example," he added.

Soviet sources close to the embassy said only 10 members of the diplomatic mission would remain in Beirut in addition to four commercial representatives. All Soviet journalists, except the correspondent of Tass news agency, also left for Damascus.

Souslikov said the evacuees would take an Aeroflot flight from there to Moscow.

Some of the departees were relaxed and could have been mistaken for a group of tourists. Two blond women reached their hands down from the windows of the freshly painted buses to husbands and friends. A few of them were crying.

The fate of Mirikov, Spirine and Svirsky remained unknown today, four days after they became the first Soviet officials known to have been kidnaped here.

The previously unknown Islamic Liberation Organization holding them warned it would execute them unless a Syrian-backed offensive against the northern Lebanese city of Tripoli was halted. A precarious cease-fire between Islamic fundamentalist militiamen and attacking leftist groups allied with Syria appeared to be holding there today after being signed yesterday in Damascus.

One Soviet diplomat watching the embassy evacuation this morning disclosed that the three remaining hostages were still alive yesterday. "We don't know anything today, but we hope they are all right," he added.

Souslikov said he found it "very strange" that the kidnapers had not tried to get in touch with the embassy to negotiate the release of the three missing officials. "We don't know where they are or who really has them," he said.

The coffin of Katkov was not with today's convoy. A diplomat explained that the "necessary documents were not ready yet."

"This is all very unfortunate," said Souslikov as he waved to the first of three buses that moved forward this morning. It was led by a truck mounted with a Soviet-made antiaircraft gun full of Druze militiamen brandishing machineguns. "I love Lebanon and I will come back," shouted a Soviet resident as he climbed into the second bus.