ISLAMABAD, Pakistan (AP) – Pakistan insisted it would help India to bring those behind the Mumbai terrorist attacks to justice, saying Thursday it had shut down extremist Web sites and suspected militant training camps, and detained 71 people in a deepening probe.

Still, a top Pakistani official said authorities needed to further investigate information about the attacks provided by archrival India before it could be used to prosecute suspects in court.

Islamabad is under pressure to clamp down on Lashkar-e-Taiba, the Pakistan-based militant group that India blames for killing 164 people in its commercial capital in the siege and raising tension between South Asia’s nuclear-armed neighbors.

Days after the November attacks, the U.N. Security Council declared that Jamaat-ud-Dawa, a charity in Pakistan, was merely a front for the outlawed militant organization.

On Thursday, Pakistan’s Interior Ministry said 71 leaders of the groups had been arrested since then and that another 124 had been placed under surveillance and must register their every move with police.

“The restrictions are so tough. It’s virtual detention,” Interior Secretary Kamal Shah said.

Rehman Malik, the ministry’s top official, said authorities also had closed 20 offices, 94 schools, two libraries and six Web sites linked to the charity. He said authorities had shut more than a dozen relief camps of the charity, some of which are alleged to be militant training grounds.

Among those detained was Hafiz Mohammed Saeed, the head of Jamaat-ud-Dawa, along with Zaki-ur-Rehman Lakhvi and Zarrar Shah, who India says planned the Mumbai attacks. Malik repeated Islamabad’s call for a joint investigation into the attacks and urged India to hand over more information to assist Pakistan’s own probe.

“We are fully committed to help India in this investigation,” he said at a news conference. “We have to prove to the world that India and Pakistan stand together against the terrorists because they are the common enemies.”

On Jan. 5, India handed Pakistan a dossier of evidence including information on interrogations, weapons and data gleaned from satellite phones used by the attackers.

India said the material proved Pakistan-based militants plotted and executed the attacks and has repeatedly insinuated that Pakistani intelligence agents were involved.

Pakistan denies that, though it has accepted that the one Mumbai gunman captured alive is a Pakistani and appears ready to accept that elements from within its borders were involved.

Pakistan has used Lashkar-e-Taiba in the past as a proxy force against India in their struggle over the divided Kashmir region. Washington says it has developed ties to al-Qaida and the West wants Pakistan to demonstrate that it has turned decisively against Islamic militancy.

British Foreign Secretary David Miliband said in Mumbai on Thursday that Pakistan, a front-line ally also against the al-Qaida and the Taliban, must show “zero tolerance” for all terror networks on its soil. Miliband plans to visit Pakistan in the coming days.

Malik said Pakistani detectives would “inquire into” the information provided by India “to try to transform it to evidence, evidence which can stand the test of any court in the world and of course our own court of law.” He appeared to rule out handing over suspects to India, saying Pakistani laws allowed for the prosecution of citizens who committed crimes elsewhere.

India indicated has that it could accept a prosecution in Pakistan if Islamabad refused to hand over suspects. “If that is not possible, there should at least be a fair trial of these fugitives in Pakistan,” Foreign Minister Pranab Mukherjee told Indian news channel Aaj Tak on Wednesday.

The United States expressed satisfaction at how the South Asian neighbors, who have fought three wars in the and had redeployed troops along their militarized border in recent weeks, were managing the fallout from the Mumbai bloodshed and urged more cooperation.

“We would like to see more the exchange of information about the Mumbai attacks so that you can get to the bottom of exactly who was responsible, see the entire plot, and hold all responsible for their actions, and make sure that in doing so you prevent any further plots from getting to the point of execution,” State Department spokesman Sean McCormack said.

In Washington, meanwhile, Pakistani Ambassador Husain Haqqani called on India to cooperate with Pakistan in what would be a joint investigation into the Mumbai attacks.

Working together, he said, would strengthen the war on terrorism and might provide access by Indian investigators to suspects held by Pakistan.

“The war against terrorism is our war, too,” Haqqani said at the Nixon Center, a Washington think tank. The audience included retired U.S. diplomats, academics and journalists.

“There are homegrown extremists on both sides of the border,” the veteran ambassador said. Cooperating in the Mumbai inquiry might lay the groundwork of restoring improved relations between Pakistan and India. They are now heading downward, a goal of the attackers, Haqqani said.