The Afghan Intelligence, National Directorate of Security (NDS), warned the US military at least twice before a deadly attack in Bagram airbase, one of the largest US-run airfield in the country, it has been reported.

Government and security sources have told Reuters that the western forces were alerted regarding a possible suicide attack by an employee working in the base.

The officials further added that the Afghan intelligence had sought information regarding the employees of the base to check for suspicious people but the request was rejected.

At least 4 people were killed and 17 others were wounded in the attack that took place earlier this month.

The United States Department of State confirmed ten days ago that two US soldiers and two US contractors were killed in the suicide attack in Bagram airfield.

State Department Press Office Director, Elizabeth Trudeau, said “In Afghanistan, we also strongly condemn the suicide attack on coalition personnel at Bagram Airfield this weekend that killed two U.S. service members and two U.S. contractors, and injured 16 other U.S. service members and one Polish soldier participating in the NATO mission.”

The Taliban militants group in Afghanistan claimed responsibility behind the attack with the reports suggesting that the suicide bomber was a former Taliban group member who had joined reconciliation process.