A Bradford mother was confronted by rats in a city-centre subway.
And now pest control officers have put down poison to trap the vermin.
A councillor has also called for an investigation.
The vermin - described as being the size of young cats - have been seen scurrying around the approach to a subway leading to the world-famous National Museum of Photography, Film and Television, which has just had an £18 million facelift.
Mrs Anne Light, 37, of Sheridan Street, East Bowling, who saw the rats said: "I am absolutely horrified that they are out in the city centre during the day when they do not normally go into crowded areas."
Mrs Light said she was glad national newspaper columnist Lynda Lee-Potter, who recently came under fire from the district's leading public figures after she described Bradford as a "vile" rubbish-strewn city, had not seen the rats.
Mrs Light said she and her husband Chris were with their sons John, 15, and nine-year-old Matthew when they saw one near the same place several weeks ago.
The Council has already produced thousands of leaflets warning that rats are becoming a problem in many parts of Britain, including Bradford. The leaflet says increased numbers of rats have been seen in both domestic and public places and can damage buildings, contaminate food and spread disease.
The rats have surfaced as Yorkshire Water carries out a programme of main replacements, but a spokesman said he did not know if the rats' appearance was connected to the work.
He said Yorkshire Water was spending more than any other water authority in baiting its sewers to catch vermin.
But Mrs Light said: "Rats spread disease and breed very quickly and it wouldn't take long for things to escalate."
Public health sub-committee chairman Councillor Marilyn Beeley said they took the complaint seriously and wanted an investigation.
She said: "Anyone with a health problem could have a heart attack seeing these things. It doesn't do the image of the city any good at all when a lot of work and money is going into improving it."
The chairman of Bradford Retail Action Group, Jeff Frankel, urged the Council to tackle the problem because it created a bad impression.
A spokesman from the Council's pest control section said there had been no rise in reports of rat sightings in the past year and they were unaware of any problems elsewhere in the city.
Converted for the new archive on 30 June 2000. Some images and formatting may have been lost in the conversion.
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