The computer hacker group Anonymous says it has broken into NATO computer servers.
On July 20-21, the group published two apparently official NATO documents online, saying "we have lots of restricted material... In the next days, wait for interesting data."
A Twitter post later claimed: "We are sitting on about one Gigabyte of data from NATO now, most of which we cannot publish as it would be irresponsible."
Germany's DPA news agency quoted an unnamed NATO official as saying the alliance was aware of the security breach, and condemning it.
Anonymous has previously been linked with Internet service attacks. Suspected group members have been arrested on hacking-related charges in Britain, Holland and most recently in the United States.
compiled from agency reports