KOLKATA (Agencies) - Indian External Affairs Minister Pranab Mukherjee on Sunday said Islamabad has to cooperate fully to bring to justice those responsible for the 26/11 Mumbai terror attack. "Pakistan must dismantle the infrastructure used by terrorist organisations in its territory to root out terrorism from the region," Mukherjee said inaugurating an international conference on 'Cooperative Development, Peace and Security in South and Central Asia' in Jadavpur University here on Sunday. "Terrorism, extremism and fundamentalism are posing a serious threat in our region. The 26/11 attack is one more example of terrorism in our region," he said. It is an imperative that all governments act to see terrorism rooted out, he said. Pointing out that internal stability in the neighbouring countries is in India's interest, Mukherjee said growth and peace were related to development. According to a report carried by The Times of India, the banned Lashkar-e-Taiba had plans to set up an operational base in a rented accommodation in posh Colaba in south Mumbai in early 2008 to coordinate the 26/11 terror plan, according to investigators. The plan could not materialise because of some reasons, and finally, the 'operational base' was set up in Room No.14, Batatawala Chawl, Nagpada, also in south Mumbai. Incidentally, Badhwar Park in Colaba where the LT planned to set up the operational base, is an exclusive multi-storeyed residential complex, housing some of the top officers of Indian Railways (IR), including high-ranking functionaries of Central Railway, Western Railway and Konkan Railway. Meanwhile, on Saturday, Indian Minister of State for External Affairs Anand Sharma made it clear that Pakistan will have to initiate steps to clear the "atmosphere of mistrust" for restarting the composite dialogue and act on the "incontrovertible" evidence provided to it in connection with the Mumbai strikes. In the backdrop of Mumbai attacks, "Pakistan needs to first initiate steps which can rebuild confidence and clear the atmosphere of mistrust for restarting composite dialogue," Minister of State for External Affairs Anand Sharma told reporters in Lucknow. Asking Pakistan to desist from creating confusion through its what he called double speak on the Mumbai terror probe, the Minister said Islamabad should fulfil its obligations to the international community.