LUCKNOW, 29 September — Friday prayers passed off peacefully at mosques across the country despite tension whipped up by a crackdown on a Muslim student group accused of trying to incite communal unrest over the US attacks crisis.

The government said yesterday it has “enough evidence” to prove that the group has links with Osama Bin Laden’s Al-Qaeda group.

A curfew remained in force in parts of the northern city of Lucknow where four youths were killed on Thursday when police fired on a protest march against the government’s decision to ban the Students Islamic Movement of India (SIMI).

Prime Minister Atal Behari Vajpayee said he was pained by the violence in Lucknow, his parliamentary constituency, and urged the country’s majority Hindus and Muslims to maintain peace.

“I am deeply pained at what has happened in Lucknow. Lives have been lost,” Vajpayee told a gathering of Muslims from the old part of New Delhi yesterday.

The shahi imam at Jama Masjid in old Delhi, Syed Ahmad Bukhari told a thousands-strong congregation that Muslims stood ready to fight alongside their brethren if the United States attacks Afghanistan, which has been sheltering the prime suspect in the attacks, militant Osama Bin Laden. “America has no right to call Osama Bin Laden a terrorist and catch him without showing proof,” Bukhari said.

But he did not mention the two-year ban on SIMI, whose president, Shahid Badr, and three associates police said were picked up at their Delhi office during overnight raids across the country.

“They were arrested as they continued to hold public meetings and provoke people for violence, despite our appeal not to do so,” Joint Commissioner of police Amod Kanth said. Badr, who was also wanted on sedition and other criminal charges, had recently attacked the government for its offer of support to the United States in its war against terrorism.

Vajpayee in his speech to the Muslim gathering yesterday said the US-led fight against terrorism had nothing to do with religion.

“I want to repeatedly assure you that this is not a fight against Islam. This is a war against terrorism. Terrorists do not respect any religion,” he said. More than 100 people were arrested in Uttar Pradesh alone after the crackdown announced by the government. In the western state of Maharashtra, police said 75 SIMI members had been detained.

According to PTI, police conducted raids on SIMI’s offices and hideouts across the country yesterday. SIMI activists were arrested in Maharashtra, Andhra Pradesh, Madhya Pradesh, Tamil Nadu and Kerala. Police sealed SIMI’s office in the eastern city of Calcutta and detained more than 20 people for questioning, Police Commissioner Sujoy Chakraborty said.

Crackdown on activists of SIMI continued yesterday across Andhra Pradesh, sources said. In Hyderabad, nine SIMI activists including four state-level leaders have been arrested and its main office has been sealed.

SIMI’s City President Athar Qureshi, Secretary Muhammad Muqimuddin Yaser, Press Secretary Ahmad Hussain and two others were arrested early Thursday, even before the ban was announced.

More than two dozen SIMI activists were arrested across the southern state of Kerala, sources said yesterday. Unconfirmed reports said police had rounded up at least 23 activists of SIMI in northern Kerala.

Police accuse SIMI of trying to stir up communal unrest over the threat of US strikes on Afghanistan, and point to the appearance of inflammatory posters — particularly in the central state of Madhya Pradesh — since the Sept. 11 attacks.

In a statement yesterday, the Home Ministry also alleged that SIMI had a “deep nexus” with the front-line Kashmiri group Hizbul Mujahedeen.

The Home Ministry statement said SIMI had been distributing pro-Taleban leaflets in major cities.

But SIMI accused the government of acting at the behest of Hindu groups allied to Vajpayee’s Hindu extremist Bharatiya Janata Party (BJP) to polarize communities in Uttar Pradesh, where crucial state elections are due by next spring.