The trial of five men accused in the Mumbai massacre that killed 166 people is likely to start next week, Pakistan's interior minister said Saturday, calling it proof of Islamabad's commitment to punishing those responsible for the assault. Several locations were targeted in last November's attacks, including the local Chabad House, where six people were killed, among them emissaries Rabbi Gavriel and Rivka Holtzberg. Rehman Malik said the investigation into the role that the five suspects played in the three-day siege of the city was "almost complete." He said the five men are in custody, and "their trial is going to commence probably next week." Malik also rejected allegations - leveled by India - that Pakistan dragged its feet in the investigation. "We have gone (the) extra mile. We have done extra investigation, and we have proved to the international community that we are sincere in investigating this matter," Malik said. "Accusations of being slow, being non serious must end today after this final investigation and the trial which is likely to commence in (the) next few days." There was no immediate reaction from Indian officials to Saturday's announcement. New Delhi blames the assault on militants trained in Pakistan and has pushed Islamabad to move swiftly to hunt down those responsible for orchestrating the attack. The US and other Western countries are also closely watching Pakistan's efforts to punish the militant suspects accused of planning and aiding the Nov. 26-28 attacks in the Indian financial center that also wounded scores. India has also demanded that Islamabad hand over the suspects, but Pakistan has rejected that call, saying it would try any suspects in its own courts. One of the five suspects, Zaki-ur-Rehman Lakhvi, has been charged with masterminding the attacks, while the four others acted as facilitators and managed funds and hide-outs used by the attackers, Malik said. "We're pretty sure, based on the evidence which we've collected, that these culprits shall be punished," Malik said, adding that the trial is to take place in a maximum security prison in the garrison city of Rawalpindi. But the minister also stressed that the case could still expand. He called on Indian officials to provide additional information, including certification of forensic evidence, DNA tests and a statement from the lone surviving suspected gunman, Agmal Kasab, who is on trial in India. Pakistan is also still hunting down a dozen other suspects in the case, who could be made additional defendants if captured. Indian security forces killed nine of the Mumbai attackers and arrested Kasab, who New Delhi said belonged to the Pakistani militant outfit, Laskhar-e-Taiba. He told investigators the militants were trained on Pakistani soil and the attack was planned there. India is pressing ahead with its trial of Kasab, who has pleaded not guilty to all charges against him, which include waging war against the country and murder. Kasab, who is said to be in his early 20s, will face the death penalty if convicted.