Hong Kong police are still negotiating with their mainland counterparts over the return of two SAR suspects held in Guangdong over the kidnap and killing of an 11-year-old schoolboy, a court heard yesterday. The negotiations were revealed as students Chan Sai-yip, 15, and Yu Ka-fai, 16, yesterday appeared for mention for the second time at Kowloon City Court on one count of conspiring to commit forcible detention. No pleas were entered. Prosecutor Annie Chan said the Department of Justice was to consider the venue for their trial and the possibility of bringing further charges against the pair. The youths were charged with conspiring with others at an unspecified location to detain Chan Chi-sin on July 11 to procure a ransom or benefit in exchange for his freedom. Ms Chan said the police had been negotiating with mainland authorities as to whether the two Hong Kong residents - arrested earlier with one mainlander in Guangdong - could be sent back to the SAR for further investigation. The two SAR residents being held in Guangdong are Luk Yan-hon, 18, and Chung Wai-yin, 28. Also detained was mainlander Yang Changgui, 20. Magistrate Ernest Lin Kam-hung adjourned the case to August 27 for the prosecution to seek legal advice. The defendants were remanded in custody. Senior Superintendent Ip Wai-keung, of Kowloon West police, said outside court the matter had been taken over by the liaison bureau. A 12-year-old girl, who was the girlfriend of one of the teenage defendants, is still on $10,000 police bail in connection with the case. The court was told Chi-sin was abducted as he left his school in Kowloon Tong. He had already been killed by the time his father paid a kidnap gang $1.4 million in ransom. It was alleged that the original ransom was $6 million. The boy's body was found on July 14 under a Kowloon Bay flyover.