A group of hackers say they breached the Central Intelligence Agency's website after it went down on Wednesday evening.

The group, known as Lulz Security, claimed credit in a Twitter message that said “Tango down – cia.gov.”

The CIA's public website experienced problems throughout the evening on Wednesday.

Lulz Security only made claims that it attacked the CIA's website, and there was no evidence on Wednesday that sensitive data in the agency's internal computer network had been compromised.

A CIA spokeswoman said the agency was looking into the report.

Lulz Security has claimed responsibility for recent attacks on the websites of the U.S. Senate, Sony Corporation, Nintendo, and the Public Broadcasting System television network.

The group is believed to be comprised of members who live across the globe. It has suggested it is trying to highlight cyber security weaknesses.