A major swimming event being held in Glasgow this weekend is going ahead as planned despite being targeted by striking workers.
Members of Unison, Unite and the GMB are picketing the Scottish Championship at Tollcross Leisure Centre.
The three-day strike is the latest action in their ongoing pay dispute over pay and conditions.
Culture and Sport Glasgow, which operates the venue, said the swimming event was "happening unaffected."
Unions said they were fighting a 10% wage cut for 150 workers, a pay freeze and cuts in public holidays and overtime rates.
Previous strikes have resulted in the closure of some of the city's most popular museums and tourist attractions, including Kelvingrove Art Gallery and Museum, the Gallery of Modern Art and the Burrell Collection.
Unison's Glasgow branch secretary Brian Smith said: "The people of Glasgow want properly funded public services, and fair pay for public service workers.
"We want Culture and Sport Glasgow to offer an acceptable 2010/11 pay rise to all its workers."
The unions have also raised concerns about health and safety arrangements at the event and said they had contacted the Health and Safety Executive to highlight the issue.
Mr Smith added: "The only Culture and Sport staff on site are managers. We think they are getting help to run the event from volunteers from the Scottish Swimming organisation.
"However, we have serious concerns that these managers, and the volunteers, have not had the necessary health and safety training specific to this building."
A spokesman for Culture and Sport Glasgow dismissed the claims and said staff had been brought in from other facilities to help run the Tollcross event.
He added: "Tollcross will be open this weekend and the UK Swimming Masters will go ahead as planned.
"The unions want to cause maximum disruption to the public, by targeting high-profile events and some of our best-loved facilities.
"On the last strike day, around one in six of our staff took action and we will work to minimise any future disruption and keep facilities open."