NEW DELHI, JULY 7 -- Thirty-four persons aboard two Haryana Roadways buses were killed in attacks close to the Punjab border tonight, bringing to at least 71 the number of Hindus slain in two consecutive nights by gunmen believed to be Sikh extremists.

Haryana state Home Secretary M. C. Gupta said late tonight that gunmen in a jeep and a car stopped one bus on a bridge near the Punjab border and dragged out and fatally shot four passengers, United News of India reported. Gupta said the gunmen later stopped a second, Delhi-bound bus on the same bridge, boarded it and killed all 30 passengers. The assailants escaped in the two vehicles.

Tonight's toll was in addition to at least 37 who died in a barrage of gunfire last night aboard another Haryana Roadways bus about 15 miles south of Chandigarh, the joint capital of Punjab and Haryana states.

The combined toll was by far the largest in a series of attacks during the past year directed mostly at Hindus, and it drew widespread condemnation from political leaders and Sikh spokesmen. Protest strikes were called for Wednesday in a number of states and cities throughout northern India, but quick security precautions in New Delhi and elsewhere kept tensions today under control.

The incidents have placed the Indian government in a vicious terrorist war with Sikh extremists, but with little or no political strategy in its arsenal to combat the root causes of the violence that has taken more than 500 Sikh and Hindu lives this year alone.

"The inhuman butchery of bus passengers should redouble our resolve to fight the extremists," said Prime Minister Rajiv Gandhi, whose government took control of Punjab from an elected Sikh state government on May 11, a step permitted under India's constitution.

President Zail Singh, a Sikh but estranged from much of the religion's more militant leadership, labeled the incident "inhuman and ghastly."

Opposition political leaders used similar sharp language, but also said Gandhi's government should share blame for its failure to resolve the crisis in Punjab involving efforts of more militant Sikhs to carve out an independent state.

A moderate Sikh community leader in Amritsar underscored the growing bitterness of Sikhs at the government's failure to try to seek a political solution and at what is widely viewed as indiscriminate police actions against Sikhs in the name of rooting out terrorism.

"This is a very unfortunate incident," the leader, Dilbir Singh, said in a telephone interview. "All human life is valuable and there is general condemnation here. . . . I have yet to find a single Sikh who is happy about it, but it is not in their hands. It is up to the government to stop it."

Since taking control of the state, he said, "The government has done nothing. It should have taken the political initiative, but Punjab Police Commissioner J.F. Ribeiro thought they could do it by declaring war on terrorism. But terrorists can strike anywhere. It is difficult if not impossible to beat the terrorists."

Singh said there is almost no political leadership being asserted in Punjab today, whether by politicians of the Sikh Akali Dal Party or those of Gandhi's independent Congress Party.

"All political parties now are irrelevant to the situation. The man in the street is helpless," he said.

Government leaders in New Delhi say they would like to strike political bargains, but the Sikh community is too divided for any effective political leadership to emerge.

"We are keen to begin a dialogue and listen to genuine demands," Gandhi said in May, "but we have two problems: first the killings must stop and then we must know who their {the militants'} representatives are."

After a day of see-sawing numbers, Ribeiro announced tonight that the toll in last night's attack stood at 37 dead and 31 injured, apparently not including one of the gunmen, who was believed killed by his companions' bullets.

Ribeiro tried to place last night's killings in the context of a successful antiterrorist campaign.

"Look, even today they can hit because they are in a tight spot because of intensified activities of security forces against them. Let us not fool ourselves," he said in a news conference in Chandigarh.

He said a letter found on the body of the gunman killed in the shooting said the incident was in revenge for the killing of innocent Sikhs. The note purportedly was from the Khalistan Commando Force, one of several militant organizations that have adopted terrorist tactics.

Ribeiro said links to the All India Sikh Students Federation also were being investigated, according to news agency accounts of the press conference.

Government spokesmen said officials believe last night's killings were an answer to the capture and killing last week of a terrorist known as Mathura Singh, as well as a number of others killed or captured in the past three or four weeks.

"When they lose a big man, they come back with their own counterattack," said one government official here.

Twenty "hard-core terrorists" have been killed and 28 arrested since New Delhi took control of Punjab's affairs, an official said. In all, 81 men have been arrested compared to a total of 131 in the previous 18 months.

"The police are more streamlined now, with better leadership," a government spokesman said. "The number of random killings is down. The terrorists are much more careful, less brazen in their attacks . . .

"But how can you prevent a mad act like this? It is difficult for the government to prevent an incident like this."

The spokesman said the government remains committed to a political solution. "The center and the state both are aware that a political solution has to be there, a lasting solution," he said. "Politically, all doors are open. The earlier we have a political dialogue, the better, but it is separate from terrorism."

While the commitment to a political solution remains on the government's agenda, its actions in the past several weeks have been directed toward a renewed police drive by hundreds of police and paramilitary personnel under Ribeiro's control. "There has to be use of force against the terrorists on the one hand and on the other an effort to isolate them, to make people more secure," the spokesman said.

Dilbir Singh, the Sikh community leader in Amritsar, expressed a feeling heard often from Sikhs, however, that many innocents get caught up in the police antiterrorist drive.

"We were told they {the terrorists} were few in number, but they keep arresting people. Most of them are eventually released because the police have no concrete cases. There is a general suspicion that much of it is a police vendetta," he said.

Special correspondent Nilova Roy contributed to this story.