Thousands of Sikhs quietly carried baskets of bricks and rubble across the marble courtyard at the Golden Temple last weekend, solemnly helping to demolish one of their most sacred shrines.

While militant Sikh activists swung sledgehammers to pound apart the walls of the Akal Takht shrine, turbaned and bearded men joined women and children in a continuous procession, carrying away baskets of debris on their heads. Led by hard-line religious leaders, Sikhs are destroying and rebuilding the Akal Takht -- the seat of Sikh religious authority -- in a ritual "purification" as part of a militant political resurgence that observers fear may threaten last year's peace agreement between Sikhs and India's government.

Meanwhile, police say they believe Sikh terrorists were responsible for two deaths in Punjab State. Late Friday, gunmen killed the son of Onkar Singh Matenangal at his home in Amritsar, the Press Trust of India said. Mattenangal is a senior member of the ruling moderate Akali Dal (party) and also serves as secretary general of the mainstream Sikh Temples Management Committee.

Gunmen also shot to death an Akali Dal supporter on Thursday, Reuter reported. At least 13 persons have died in Sikh-related violence this month.

Last September, voters here in Punjab, the Sikhs' home state, swept the moderate leaders of the Akali Dal into power in what seemed a clear rebuff to the militants. But the militant Sikhs, who oppose the Akali Dal's compromise peace accord with Prime Minister Rajiv Gandhi, are raising what political observers say is their strongest challenge yet to the Akali leaders and the Sikh religious establishment.

Late last month, the militants held a mass meeting at which they took control of the Golden Temple and declared that they had removed its high priests from office. They also took charge of the symbolically important destruction of the Akal Takht, one of the central shrines within the temple complex.

Although state government and mainstream Sikh religious leaders condemned the takeover, they have not tried to oust the predominantly young extremists. Instead, they have called a mass meeting of the Sikh congregation at the temple next Sunday to reaffirm their leadership, raising fears of a violent clash between the two sides.

Several political observers here said that by forcing the Sikh political and religious establishment to call next Sunday's meeting, the militants had set the stage for a referendum on the moderates' leadership at a time when the moderates' popularity may be slipping. While they agreed that the extremists had taken the political offensive, analysts remained unsure that they had captured new support among the Sikh masses, some suggesting that there had been public disapproval at the militants' use of the Golden Temple for a political campaign.

The militants' action puts heavy pressure on the state government, whose survival is seen as essential to maintaining the peace process in Punjab. The state's chief minister, Surjit Singh Barnala, conceded last week that the extremists had guns, but he has said he would not send police into the temple complex.

Political observers here and in Punjab's capital, Chandigarh, agreed that any use of force would outrage the Sikh community, as it did when the Indian Army assaulted the temple in June 1984. At the same time, observers argue that the militants' continued control of the temple is giving them a prominent platform from which to campaign against the community's established leadership.

The Akal Takht was heavily damaged when Indira Gandhi, then prime minister, ordered the 1984 Army assault, which two Sikh policemen avenged four months later by assassinating her. The government then had the shrine rebuilt at its own expense.

Many Sikhs, angry at what they regarded as the government's desecration of the temple, have argued that the Akal Takht must be demolished and rebuilt by the hands of the Sikh faithful -- a process that the militants have now begun.

"The work of Indira Gandhi was to desecrate the Akal Takht," a middle-aged housewife from Amritsar said bitterly, "and our work is to restore its purity." She expressed support for the Sikh militants and disapproval of the moderates in the state government who the militants said are failing to protect Sikh interests.

Sikh religious authority is vested in a 160-member committee that manages temples in India and appoints the religion's high priests. The current committee largely opposes the Sikh religious fundamentalists and political militants who have campaigned for religious reforms and, some of them, for an independent Sikh state.

But militants charge that the committee is corrupt and has offered no valid reason for failing to hold committee elections, which were due in 1983. The committee claims that conflict within the Sikh community precluded elections.

Political observers here suggested that Sikh public opinion has shifted against both the religious establishment and moderate politicians since last fall's state elections. The militants then called for a boycott of the polls, a move widely seen as a miscalculation after a heavy turnout gave the Akalis a strong victory over the predominantly Hindu Congress (I) Party of Prime Minister Gandhi.

"The people wanted to vote as a form of revenge against the Congress (I), even if they didn't enthusiastically support the Akalis -- but that vote did not mean they had completely turned against the extremists," a Sikh journalist here said.

According to virtually all Sikhs interviewed, the Akali Dal has appeared increasingly as the collaborator of the New Delhi government rather than as the champion of a community that they feel is the victim of injustice.