Chinese forces are certain to attack Vietnamese troops if they remain entrenched on a hill just inside Chinese territory near the troubled border between the two countries, sources here closer to Peking said yesterday.

"We must push them back," said one source who said China was using a favorite military tactic in letting the Vietnamese move into Chinese territory and waiting before retaliating.

The official Vietnamese News Agency meanwhile quoted the Central Committee of the Vietnam Fatherland Front, a coalition of mass organizations, as saying the Vietnamese people "want a lasting friendship with the Chinese people but the Chinese authorities have pushed them into a position where they are left with no alternative but to react violently."

A Hong Kong source with ties to Peking referred to China's brief and successful border war with India in 1962 as an example of how Peking would handle the reported Vietnamese incursion.

In 1962 the Indian government adopted a "forward policy" in disputed sections of the mountainous border between the two countries and sent its troops into areas claimed, though lightly defended, by the Chinese. For a while the Indians met little resistance, then the Chinese suddenly counterattacked in force, sweeping the Indians back far behind their original lines.

"We let them come in and then suddenly, we attacked and took 5,000 prisoners," the source recalled. A month after they began their assault, the Chinese just as abruptly stopped, pulled back and released all their prisoners, having sufficiently chastized the Indian government.

Foreign analysts here said they felt the Chinese were waiting also to see if the Vietnamese would pull back voluntarily. It is not known whether the Vietnamese troops are still in Chinese territory. The last report on the situation by the official New China News Agency, released Monday, described Vietnamese movements in the vicinity of Bonien Hill on Saturday.

Following a violent scuffle Friday in the Friendship Pass border area during which two Vietnamese officials and at least Seven Chinese refugees were reported killed. China said 400 Vietnamese troops occupied Bonien Hill, which is in Chinese territory and overlooks the pass.

China said Friday's events, the most serious and potentially dangerous in months of border strife, had "aroused great indignation" among Chinese soldiers and civilians in the area, but gave no clue what action it would take.

Hanoi, while blaming China for Friday's bloodshed, has said nothing publicly so far about the alleged border incursion.

Monday Radio Hanoi said it had captured six Chinese boats in Vietnamese waters on Aug. 13, referring to their presence as a "provocation act."

The official Vietnamese news agency said yesterday that "the Chinese side took more provocative acts" Sunday by sending boats to the Vietnamese side of a river border in Quangninh Province and "taking away properties of a porcelain factory and local co-ops."

The Chinese agency had said the Vietnamese had sent scouts as deep as 1,000 yards into Chinese territory and had thrown rocks down on Chinese border officiala from the hilltop. There were no reports of firearms being used. Friday's deaths were attributed by both sides to soldiers and police using clubs, stones, daggers and bayonets.

Analysts here said they found it hard to explain Hanoi's action in moving into Chinese territory. They said it was unlikely there was any misunderstanding about where the border was located in that area, since it was so close to a major checkpoint.

Souces here close to Peking blamed the incident on the Soviets. "They are using the Vietnamese like Cubans," said one.

Moscow had been putting out particularly vehement progaganda against China in the last several days, apparently in retaliation for Chinese Communist Party Chairman Hua-feng's state visit to Romania, Yugoslavia and Iran. The Soviets see Hua's action as an attempt to win over countries strategically near western Soviet borders.

Hua arrived in Iran yesterday for the last leg of his trip. There was no indication he planned to cut short his three-day stay there to rush back and handle the Vietnamese border problem.

New Services reported the following:

China accused Vietnam yesterday of declaring "military forbidden zones" in some border areas to force out ethnic Chinese living in them.

The official New China News Agency said orders to move out Chinese had been issued earlier this month. It described the atmosphere on the border between the two countries as tense.

In other developments:

Cambodian radio implicitly confirmed that fighting between Cambodia and Vietnam has intensified recently. It said revolutionary troops and the Cambodian people continued their heroic battle against "the Vietnamese invaders," but gave no details of the fighting.

Hanoi Radio said Vietnamese Premier Pham van Dong will visit Thailand soon at the invitation of Thai Premier Krangsak Chamanand.