A tiger that escaped from its cage at a Northern Ireland zoo last night attacked and injured a zookeeper before being shot dead by police, an RUC spokesman said. The zookeeper was trying to use tranquillisers to recapture the animal in the grounds of Bellevue zoo but it attacked him.The police spokesman said: "The zookeeper is presently in hospital being treated for injuries to both legs and a hand. The tiger died in the incident."