Two salesmen were attacked and robbed of one of two briefcases - each containing diamonds worth $10 million - in Causeway Bay yesterday by two men who bashed their heads with metal bars. Police later captured one of the suspects on a bus in Wan Chai, but failed to find any of the diamonds. The salesmen, both employees of Israeli-owned jeweller EMA Asia Ltd in Wellington Street, Central, were taken to Tang Shiu Kin Hospital where they were treated for head injuries and later discharged. The two were last night helping detectives with their investigations. Richard Poon Suet-man, Wan Chai assistant divisional commander (crime), said the robbery occurred at about 4pm. The salesmen were each carrying briefcases with diamonds to show to potential buyers at jewellery shops in Causeway Bay and Wan Chai. As they were walking outside Kam Luen Medicine Shop at 72 Percival Street, the two men jumped out behind them and hit them over the head. The robbers managed to snatch the briefcase from a local employee and fled, but they failed to grab the other held by his Israeli colleague. A witness told police that the robbers fled in different directions. One of the attackers was reported to have fled towards Russell Street and later disappeared, while his accomplice fled towards Victoria Harbour and was seen jumping on to a bus travelling towards Wan Chai. Officers later intercepted a bus in Lockhart Road near the junction with Fleming Road and arrested a 26-year-old mainlander on a two-way permit. Police found bloodstains on his shirt but no sign of the diamonds. The suspect was in detention assisting inquiries at Wan Chai police station last night. Officers later recovered a metal bar wrapped in bandages near a convenience store. Investigators believe the culprits wrapped the metal bar to avoid leaving their fingerprints on the weapon. District Crime Squad officers were last night continuing their search for the escaped attacker who they believe is in possession of the multi-million-dollar diamond consignment.