MUZAFFARABAD, Pakistan, (Reuters) – Pakistan shut offices and arrested scores of activists of an Islamic charity, officials said on Friday, as international pressure mounted for firm action against militants blamed for the Mumbai attacks.

The overnight raids came after Pakistan said it would abide by a U.N. decision placing Hafiz Saeed, founder of the Lashkar-e-Taiba militant group, on its terrorism sanctions list of people and organisations linked to al Qaeda and the Taliban.

India and the United States have been urging Pakistan action after the Mumbai attack by gunmen that killed 179 people last month.

U.S. Deputy Secretary of State John Negroponte met with Pakistani political leaders and army chief General Kayani before going to New Delhi on Friday, as Washington kept up intense diplomatic efforts to keep Pakistani-Indian relations from worsening and Islamabad focused on the war on terrorism.

Saeed, who founded Lashkar in 1990 and officially left the jihadi group in 2001 just days before Pakistan banned it, has been put under house arrest, according to one of his spokesmen.

Three associates were also added to the U.N. list and will be subject to sanctions freezing assets and restricting travel, but a Pakistani television news channel reported one of them was dead and another had been in a Saudi jail for the past three years.

An intelligence official told Reuters that Maulana Masood Azhar, head of the Jaish-e-Mohammad group blamed with Lashkar for a 2001 attack on India’s parliament, was also detained.

One close aide of Azhar’s told Reuters: “I think they could have detained him to relieve pressure, but I don’t know the exact whereabouts of the Maulana.”

In the Pakistani Kashmir capital Muzaffarabad, police raided an office, two schools and a religious seminary run by Jamaat-ud-Dawa (JuD), a charity regarded as a Lashkar front. The U.N. has put the JuD on its terrorist list too.

Hundreds of supporters, and people who recalled JuD’s work during an earthquake in Kashmir in 2005, protested the raids. “Pakistan should revisit its policy of bowing before international pressure immediately, without regard for the pros and cons of its actions,” Maulana Abdul Aziz Alvi, JuD’s head in Pakistani Kashmir, told Reuters from house arrest.

Police raided JuD offices elsewhere in Pakistani Kashmir, as well as in several cities including Multan, Bahawalpur, Rahim Yar Khan, Lahore, Karachi and Quetta. A Jamaat spokesman said 100 workers were arrested in North West Frontier Province alone.

The charity’s headquarters at a sprawling complex in the eastern town of Muridke appeared deserted. Officials said the office, schools and hospitals it ran there had shut on Dec. 4.

A spokesman for Pakistan’s central bank said late on Thursday that directives had been issued to banks to freeze JuD accounts and assets of the four men added to the U.N. sanctions list.

Television reports said the JuD would be banned though no official announcement has yet been made.

In Mumbai, thousands of people formed a human chain starting from sites where the gunmen had attacked and going on for miles.

Schoolchildren in uniforms, office workers, city employees, commuters and senior citizens, many with posters pinned to their clothes, held hands and shouted slogans against terrorism and government inaction for 15 minutes from noon.

Indian Prime Minister Manmohan Singh told parliament on Thursday that Pakistan needed to do more.

Assistant U.S. Secretary of State Richard Boucher, after meeting Chinese officials in Beijing, said Pakistan’s moves were “good steps”. “But you also have to find out who else was trained and what else might they have planned, and so I think we want to keep working with Pakistan and make sure that other threats, other dangers, other terrorists, can be stopped,” he told reporters.

A Pakistani crackdown on Jaish and Lashkar after the 2001 attack on India’s parliament was regarded as a sham, and India will be looking for more concrete and lasting steps this time.

Analysts say the question is whether Pakistan’s military would be willing to abandon support for jihadi groups who have helped them fight India in the past.

Pakistan said it is investigating alleged links with the Mumbai attack, but India has not provided any evidence. “Our own investigations cannot proceed beyond a certain point without provision of credible information and evidence pertaining to the Mumbai attacks,” Foreign Minister Shah Mehmood Qureshi said in a televised statement early on Friday.