Lockheed Martin and the Department of Homeland Security confirmed Saturday night that the contractor had come under a cyber attack.

Chris Ortman, speaking for Homeland Security, said his agency and the Defence Department are trying to determine the extent of the data breach. He said the agencies are analysing data and working to recommend ways to address the attack and mitigate the problems.

Lockheed Martin said in a late evening statement that the company's security team detected the threat quickly and no customer, program or employee personal data had been compromised. The Pentagon said the impact on its operations is "minimal."