Two public leisure centres in Lincoln have closed after the charity that runs them ceased trading, a council has confirmed.

Active Nation confirmed the closure of the Yarborough and Birchwood leisure centres in an email to members on Wednesday night.

The operator blamed "the ongoing utility crisis and the challenges it has created".

The City of Lincoln Council, which owns both buildings, described the situation as a "sad development" and said it was "assessing available options".

Active Nation said it held talks with the council about the closures, but an alternative operator had yet to be found.

In a statement, the registered charity said: "We regret to inform you that no alternative providers have been identified for transferring services, which means the centres will remain closed for the foreseeable future.

"We are deeply disappointed by this outcome."

Carla, an instructor, told BBC Radio Lincolnshire she had taken classes at the Yarborough Leisure Centre hours before the email about the closure was sent.

She said: "We didn't know anything about it. The place was buzzing and it was busy but then we got the news.

"The biggest thing is the staff and how are they going to pay their bills. Yarborough and Birchwood are communities. For some people it's a second home."

The City of Lincoln Council said staff at both venues had worked hard to keep them running during "tough trading conditions".

"Their announcement will no doubt cause considerable concern to users of those two facilities, and of course to the staff employed in them," it added.

The authority also advised people with pre-paid memberships of the centres to contact their bank or card provider.

The council told the BBC that the Lincoln 10K, which is due to take place on Sunday and starts from Yarborough leisure centre, would go ahead as planned.

Active Nation, a charity based in Warwickshire, also operated facilities in Southampton and Aldershot.