New Delhi, Aug 31 (IANS) Prime Minister Manmohan Singh arrived here Friday after a four-day visit to Tehran during which he attended the 16h summit meeting of the Non-Aligned Movement and held bilateral meetings with the presidents of Iran and Pakistan.

At the meeting with Pakistan President Asif Ali Zardari Thursday, Manmohan Singh said that expeditiously concluding the trial of the perpetrators of the 26/11 Mumbai attack would be the biggest confidence building measure between the two neighbours.