Chester Zoo was evacuated this afternoon after 30 chimpanzees escaped from their enclosure. The animals found their way into a keeper area where their food is prepared at 12.40pm. More than 5,000 visitors were asked to leave the 110-acre zoo shortly afterwards, as keepers rounded up the chimps. There were no injuries to members of the public or staff and the decision was taken purely as a precautionary measure, the zoo said in a statement. "We apologise for any inconvenience this has caused to our visitors and would thank them for their full co-operation and patience," the statement said. The zoo has more than 1.3 million visitors a year and has been named by Forbes as one of the best 15 zoos in the world.