ISLAMABAD, Pakistan - Pakistan has intensified its crackdown on a militant group suspected in the Mumbai terror attacks by arresting 20 more people but will not hand any of its citizens over to India, officials said Tuesday.
The United States is pressing Pakistan to help catch those behind the attack, which killed 171 people in India's business capital last month, and avert a crisis between the nuclear-armed neighbors that would harm efforts against the Taliban and al Qaeda.
A senior Pakistani security official said troops raided at least five more offices of militant group Lashkar-e-Taiba in Pakistan's portion of the disputed region of Kashmir in the past 24 hours.
Security forces were acting on information gleaned from Zaki-ur-Rehman Lakhvi, an alleged mastermind of the attacks who was picked up in the same region on Sunday.
The official said none of the latest 20 people detained were among those named by India in connection with the Mumbai carnage.
A Lashkar-e-Taiba official confirmed that there had been more raids on their offices, but declined to elaborate.
Both sources asked for anonymity because of the sensitivity of the issue.
Pakistani authorities have not publicly confirmed the names of those arrested since the raids got under way on Sunday. However, government and intelligence officials have confirmed that they include Lakhvi and several other members of Lashkar-e-Taiba.
President Asif Ali Zardari said the raids were a sign of Pakistan's resolve to help in the investigation.
Peace talks that have eased tension with India in recent years must move forward to "foil the designs of the terrorists" who struck in Mumbai, he wrote in an opinion piece published in The New York Times on Tuesday.
"Pakistan is committed to the pursuit, arrest, trial and punishment of anyone involved in these heinous attacks," he wrote.
Indian officials have named Lakhvi and another Lashkar-e-Taiba commander as orchestrators of the attack. India also presented Pakistan with a list of other terror suspects and demanded their extradition.
However, Foreign Minister Shah Mehmood Qureshi said Tuesday that none of those detained so far would face justice in India.
"They are Pakistani citizens and will be dealt with according to the law of the land," Qureshi told reporters in his home city of Multan. "No arrested Pakistani would be handed over to India."
Qureshi said Pakistan was still waiting for Indian authorities to respond to its offer of a joint investigation.
Analysts say Lashkar-e-Taiba was created in the 1980s with the help of Pakistan's intelligence agencies, which used it as a proxy fighting force in Indian Kashmir.
The dispute over the divided Himalayan region has triggered two of the South Asian rivals' three wars since 1947. An attack on the Indian parliament in 2001 also blamed on Lashkar-e-Taiba brought the countries close to a fourth conflict.
However, tensions eased palpably under a peace process begun in 2004.
U.S. officials fear another serious disruption in relations would dent hopes for regional stability needed to keep Islamabad focused on fighting Islamic militants along the Afghan border.
Analysts have said the peace process would likely be halted for several months or longer due to tensions triggered by the attacks, but no one on either side had formally suggested abandoning the negotiations.
Many experts suspect Pakistan's intelligence agencies have maintained some links with Lashkar and other militants, either to use them against India or in neighboring Afghanistan, but U.S. counterterrorism officials say there is no evidence linking Pakistan state agencies to the Mumbai attacks.
Indian officials say the sole Mumbai attacker captured alive has told them that Lakhvi recruited him for the mission and that Lakhvi and another militant, Yusuf Muzammil, planned the operation.
India has not commented on his reported arrest. State Department spokesman Sean McCormack did not confirm it, but said the raid was a "positive step."
The United States says Lashkar is linked to al Qaeda. In May, the U.S. blocked the assets of Lakhvi and three other alleged members of the group, including its leader, Hafiz Mohammed Saeed.
Pakistan banned the group in 2002 following U.S. pressure, but there have been few if any convictions of its members. An Islamist charity called Jemaat-ud-Dawa sprang up after the ban, which U.S. officials say is a front for the group.
Jemaat-ud-Dawa -- which denies any link to Lashkar -- runs a chain of schools and clinics throughout the country and has helped survivors of two deadly earthquakes in recent years.
Moving against that network amid pressure from the U.S. and traditional rival India risks igniting Muslim anger that could destabilize the county's shaky, secular government at a time of surging extremist violence elsewhere.
On Tuesday, a suicide bomber blew himself up, apparently prematurely, killing a child and wounding four others in northwestern Pakistan, said police official Mohammed Hanif. The blast occurred in Swat, a valley close to the Afghan border where militants are fighting troops to pressure the government to enforce a hard-line version of Islam.
