(Reuters) - A nationwide AT&T wireless outage in February that lasted for more than 12 hours blocked more than 92 million voice calls and prevented more than 25,000 attempts to reach 911, the U.S. Federal Communications Commission said in a report seen by Reuters.

The FCC, which has been investigating the issue for five months, said it had referred the matter to its Enforcement Bureau for potential violations of FCC rules. The FCC said all voice and 5G data services for AT&T wireless customers were unavailable during the outage. AT&T did not immediately comment.