The US Department of Homeland Security is advising citizens to use alternatives to Microsoft's Internet Explorer web browser until the company fixes a security flaw that hackers have used to launch attacks.

The United States Computer Emergence Readiness Team (US-CERT) said in an advisory that the vulnerability in versions 6 to 11 of Internet Explorer "could lead to the complete compromise of an affected system".

Microsoft warned customers over the weekend that a vulnerability in its Internet Explorer browser could allow hackers to gain access to their computers.

The flaw affects Internet Explorer versions 6 to 11, representing more than a half of the global desktop browser market, according to NetMarket Share. Microsoft said that it was aware of "limited, targeted attacks" that exploit the flaw.

"An attacker who successfully exploited this vulnerability could take complete control of an affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights," the company said in a security advisory.