Security has been stepped up around the US consulate and the American Center here in the wake of reported threats of terror attacks on US targets in the country, particularly New Delhi and Mumbai.

Deputy commissioner of police Sanjoy Mukherjee said security had been tightened at the American Center, which was attacked in January 2001 by armed gunmen who killed five policemen, and he consulate a little distance away.

In a related development, West Bengal Inspector General of Prisons Joydeb Chakraborty said Aftab Ansari, prime accused in the American Center attack case, and his two associates have been shifted to Presidency Jail from Alipore Jail for security reasons.

The move followed information a few days ago that the three had developed "a nexus with some wardens and criminals in the jail", Chakraborty said.

"Presidency Jail is in the heart of the city and is more protected. It would be easier for jail officials to monitor Ansari's movements from there," he said.

As a precautionary measure, authorities have also made arrangements inside the jail for Ansari's trial.

--Indo-Asian News Service