MANCHESTER, N.H. — FairPoint Communications says a problem that occurred during routine maintenance led to a loss of high-speed Internet service for thousands of customers in Vermont and New Hampshire on Thursday.

Spokesman Jeff Nevins says the hardware problem knocked out service for all of Vermont and part of New Hampshire on Thursday morning.

With about 1,800 FairPoint workers on strike in Maine, New Hampshire and Vermont, a management employee was performing the maintenance late Wednesday on equipment that routes Internet traffic. The first outages were reported early Thursday.

Nevins said service is being restored. He said customers can reboot their modem if their service isn’t restored automatically.

He couldn’t say how many customers lost service in Vermont and New Hampshire. Maine customers were not affected.

Jennie Angell, director of information systems for the City of Manchester, said an outage was detected around midnight on the city’s FairPoint Internet link. She said a partial outage affected access to the city’s website until about 11 a.m.

The outage also affected computers in police and fire vehicles, so a police officer couldn’t look up a license plate, for example. They still had radio communication. Email was not affected.

Angell said the city has multiple Internet access resources, so it was able to move some critical, in-house items, such as car registrations, over to Internet access that was working.

“We haven’t had an Internet outage in a number of years,” she said.

The city of Nashua’s website also was down until about 11:15 a.m.

The FairPoint workers have been on strike since Oct. 17. The North Carolina-based company imposed its best and final offer in August after declaring an impasse.

“We’re striking so these outages don’t become the new future at FairPoint,” said Don Trementozzi, president of Communications Workers of America Local 1400.