LONDON –  A three-year-old boy critically injured in a zoo enclosure was attacked by a crocodile, the BBC understands. Cambridgeshire Police said a 30-year-old man arrested on suspicion of attempted murder had been bailed and was “unfit for interview”. He reportedly has learning disabilities and had been on a trip to Johnsons of Old Hurst, near Huntingdon, with carers. It is believed the boy was attacked on Thursday by at least one crocodile after ending up in their enclosure. He remained in a critical but stable condition. Police said the boy, who was from Cambridgeshire and visiting with his family, sustained serious injuries “while in the enclosure” and was pulled out by zoo staff. He received medical treatment at the scene before being taken to Addenbrooke’s Hospital in Cambridge. Officers said they were called to the zoo at 13:34 BST on Thursday and were working to establish how long the boy was in the enclosure. Police said the crocodiles had not been seized or killed. Det Insp Verity McCann said: “Our inquiries are ongoing as we continue to understand the circumstances surrounding this distressing incident. “Our thoughts remain with the boy, and his family and specialist officers continue to support them through this difficult time.” The man who was arrested was from Norfolk, police said, and was not at the zoo as part of an organised group visit.  People may be considered not fit to be interviewed because of their physical or mental state. A witness told the BBC she had seen a man in his late 20s, accompanied by two women wearing lanyards who she believed may have been carers, walking through the zoo about 10 minutes before the incident. She said they crossed paths as she and her daughter were entering the capybara enclosure and the group was coming out on to the forest walk. The witness said she overheard one of the carers ask: “Should we go to the crocodile house next?”. The man replied: “Yeah.”