Pakistan has launched a crackdown on jihadist groups that it claims is more resolute than those of previous governments, who felt “no urgency” to fight organisations that were targeting India, a senior minister has said.

More than 120 people have been taken into administrative detention and at least 200 schools, seminaries and hospitals have been seized by the government this week as part of a campaign against banned Islamist organisations.

The arrests and asset seizures, the most sweeping in years, targeted Islamic schools and charities considered fronts for United Nations-blacklisted militant groups that have operated with near impunity in the country.

International pressure has been mounting on Islamabad after a suicide bombing in disputed Kashmir by the Pakistan-based militant group Jaish-e-Mohammed sparked a series of tit-for-tat airstrikes between India and its neighbour and the first dogfight between their jets in nearly 50 years.

Jamaat-ud-Dawa (JuD), a welfare organisation regarded as a fundraising organ for the militant group Lashkar-e-Taiba, was officially banned this week and had its headquarters in Lahore sealed.

“A crackdown against us is under way,” said Yahya Mujahid. “Our offices, schools, medical facilities and ambulances are being taken over by the government. But our leadership has directed activists and supporters to remain peaceful.”

Hafiz Saeed, Lashkar-e-Taiba’s chief, was banned from leading prayers on Friday at the sprawling white JuD complex in one of Lahore’s busiest areas.

“JuD activists did not resist us,” said a senior police officer, one of dozens who were posted at the site on Friday morning. “In the next few days, we plan to take over JuD-run mosques, there are hundreds of them in Lahore alone.”

India has expressed scepticism that the latest crackdown is different to earlier campaigns of arrests and closures that did little to disrupt the organisations.

After the 11 September 2001 terrorist attacks, and again following the 2008 Mumbai attacks that killed 166 people, the Pakistani government promised to shut down groups such as JuD. But they have continued to operate openly from the country’s most populous province, Punjab, and expanded to remote corners of the country.

“Previous governments were not serious about cracking down on these anti-India groups, because these guys did not pose a serious challenge to Pakistan, so there was no urgency to work on them,” said Fawad Chaudhry, Pakistan’s information minister.

“But we have said that now we won’t let even these organisations work here. No militant organisations can work from Pakistan anymore.”

He said militant leaders such as Saeed were “under watch”, adding: “We are trying that things can be resolved and settled with them in a peaceful manner. And if we can’t settle things peacefully … we will use the full force of the law against them.”

Chaudhry said the government was ready to give surrendering militants jobs and business loans, accommodate them in government-run religious schools and mosques and allow them to enter mainstream politics.

The key difference with this latest crackdown was that Pakistan’s civil government and its powerful military were invested, he added. “This time around the army leadership and the civilian leadership both have the same vision,” Chaudry said. “This has never happened in the past.

An official in Delhi said the Indian government would not be convinced that Pakistan was serious until it took “steps which can be verified”, such as closing down the accounts of militants groups, prosecuting leaders implicated in terrorist attacks and liquidating assets.

Pakistan has successfully quelled groups such as the Pakistani Taliban that have conducted attacks on its soil. But tackling anti-Indian militants will be harder. Delhi says such groups are nurtured by the country’s security establishment for use as proxy fighters across the border – a charge Pakistan denies.

Many Islamic charities accused of being fronts for militant organisations also provide the only education, healthcare and emergency services available to millions of poor Pakistanis.

A major earthquake in Kashmir in 2005 and a national flood crisis in 2010 opened a fresh opportunity for Islamic charities such as JuD to demonstrate they could provide the relief services that the government could not – services that helped them to lure new recruits to banned militant groups.

With public education in shambles, Pakistan’s poorest families often turn to Islamic schools that feed and house their children but also push a more militant brand of Islam on them.

Chaudry said earlier attempts at cracking down on the groups were hampered by regional factors and internal security problems.

“There is a war going on with Afghanistan that we are getting the blowback off,” he said. An insurgency was also raging in the restive province of Baluchistan. “So we are already stuck in all this and now you want that we should have also pushed these [anti-India] groups to turn against us?” Chaudry said. “This is a catch-22 for us.”

A western diplomat in Delhi said the US, UK, France and others had been urging Islamabad to crack down on militants operating on its soil, which they regarded as “the greatest risk to regional stability”.

This was especially so after the Indian government made clear that further attacks would provoke a strong response – which in turn would likely trigger a Pakistan counter, raising the risk of a wider conflict.

While tensions between the two countries had appeared to calm, “if there is no Pakistani action against terrorists and there was another attack in India frankly I don’t know where the situation would go,” the official said.