ISLAMABAD — Pakistani officials took what could be a decisive step forward in the country’s fight against Islamic extremism Thursday, publicly admitting for the first time that the Mumbai terrorist attacks were planned in and launched from Pakistan.

“Some part of the conspiracy has taken place in Pakistan,” Rehman Malik, the top security official in the Interior Ministry, told a news conference in Islamabad. “I want to assure the international community, I want to assure all those who have been victims of terrorism, that we mean business.”

Before the announcement, Pakistani officials had denied that there was any proof that its citizens were involved in the November Mumbai bombings, which killed some 170 people and pushed nuclear-armed Pakistan and India to the verge of war. Indian officials Thursday promptly welcomed the Pakistani admission as a “positive development.”

The steps Malik outlined could be Islamabad’s most serious action yet against militant groups, and they coincided with a visit this week from the Obama administration’s new special envoy for Afghanistan, Richard Holbrooke. Washington has long pressed Pakistan for tougher measures against extremists, but some Pakistani military and intelligence officials have been reluctant to take action against Islamist groups when they consider India to be Pakistan’s main enemy.

Malik said that Pakistan has eight suspects in the Mumbai attacks, including the alleged mastermind, who are together accused of orchestrating the attacks. Six of the eight are in custody, and criminal cases were filed against them on Thursday. The interior ministry said that most, and possibly all, of the conspirators belonged to Lashkar-e-Taiba, a Pakistan-based militant group that Indian officials have accused of carrying out the Mumbai carnage.

Malik said the ringleader, Hamad Amin Sadiq, a 38-year-old he described as the “main operator”, was among those in custody. Sadiq wasn’t previously named as a suspect. A resident of Karachi, he’s originally from the southern Punjab province, a hotbed of Islamic militancy.

Pakistani authorities found one of the boats used by the Mumbai assailants and the crew, confirming that the terrorists set off from Karachi. They located the shop in Karachi where the attackers bought a boat engine to power the inflatable craft they used to land in India, and that led them to an arrest and to the bank account used for payment, Malik said.

Investigators also discovered that the attackers had made extensive use of Internet and telephone communications from Texas to Europe and the Middle East. A man named Javed Iqbal who lived in Barcelona, for instance, set up some of the Internet phone accounts _ which were paid for in Italy. Iqbal was “lured” back to Pakistan during the investigation and detained, officials said. The attackers in Mumbai used phones to keep in touch with their handlers throughout the operation.

Malik stressed that the conspirators were “non-state actors,” a response to Indian allegations that Pakistan _ especially its Inter-Services Intelligence agency _ helped orchestrate the attack.

The leaders of Lashkar-e-Taiba, including founder Hafiz Saeed, were placed under house arrest soon after the Mumbai attack, but they aren’t part of the Pakistani probe. The fate of Saeed, a powerful figure who in the past was said to have ties to ISI, remains unclear.

Ten gunmen attacked Mumbai, but the only one caught alive was Ajmal Kasab, who has made a lengthy confession to Indian authorities. The Pakistani investigation had been unable to trace the origins of any of the nine who were killed, saying Thursday that India hadn’t provided enough information on them. Islamabad said it has submitted 30 questions to Indian authorities, whom it says have withheld notes from Kasab’s interrogation and other evidence.

“We will continue our investigation, but we want tenable evidence from India. We want full cooperation from India so that this kind of ring be smashed,” said Malik.

There appeared to be divisions among the Pakistani authorities on how much to cooperate with India, and a senior official was fired last month for confirming that Kasab was a Pakistani, although a McClatchy Newspapers investigation had traced him to his home village in Pakistan.

“If somebody here is involved in terrorism, and there is ample evidence about it, why cover it up?” said Ikram Sehgal, a security analyst based in Karachi. “They (the Pakistani government) could have said these things earlier but it’s better late than never.”

(c) 2009, McClatchy-Tribune Information Services.