An Indian fisherman who was aboard a boat shot at by the U.S. Navy in the Persian Gulf has told officials that his crew did not receive any warning before the attack.

One Indian was killed and three others were wounded Monday when the U.S. Navy refueling ship fired on the fishing vessel. U.S. officials say the small boat had ignored repeated warnings and rapidly approached the U.S. vessel.

Indian Foreign Minister S.M. Krishna said Tuesday it was unfortunate that a fisherman was killed in the incident. He said his government is in contact with India's ambassadors in Washington and Dubai and that the United Arab Emirates is investigating the incident.

The United States has been expanding its forces in the Gulf as it seeks to increase pressure on Iran over its disputed nuclear program.

On Tuesday, Iran said the recent shooting incident showed that foreign forces threatened regional security.