Kolkata attack 'suspects' killed

Guards patrol the American Center in Kolkata

NEW DELHI, India (CNN) -- Indian police have shot and killed two men in eastern India blamed for a deadly shooting attack last week on the American Center in Kolkata, India's home secretary Kamal Pande said.

The two men killed in a pre-dawn raid Monday were Pakistani nationals with links to Pakistan's Inter-Services Intelligence, or ISI, Pande said. India blames the Pakistani intelligence agency for supporting extremist groups that carry out attacks on India.

Four Indian policemen were killed in the Jan. 22 shooting and at least 20 others injured, when two men armed with AK-47s drove up to the building on a motorcycle and started firing at the police who guard the center in Kolkata, formerly known as Calcutta.

The building houses a number of offices, including the U.S. consulate's press office and cultural center, but U.S. officials said the attack was not against the United States.

Indian police staged the raid at a building in Hazaribagh, about 350 kilometers northwest of Kolkata, where the two men were hiding, Pande said.

"Police and security agencies of the various states concerned had been on alert and they were aware of certain hide-outs and certain suspicious movements of people in these hide-outs," Pande said.

"The police became more suspicious when they found that the persons in this hide-out whom they had been keeping a watch on were missing from 18th of January and returned only on the 24th or so."

Pande said one of the men had admitted his involvement in the Kolkata shooting, but did not say who he confessed to.

An AK-47 believed to be used in the attack was recovered from the building, Pande said.

--CNN New Delhi Producer Rohit Gandhi contributed to this report