Information sought in cases of a teen student, taxi driver and an unknown woman Police have offered rewards totalling $900,000 in an attempt to solve three out of four homicides committed last month. No reward has been offered for the fourth as investigators are said to be following some promising leads. The three rewards are among $7.8 million worth of bounties on offer for 17 unsolved homicide cases listed on the police website. A $300,000 reward was posted this week for information about the killing of taxi driver Xa Siu-fok, 55, whose charred body was found in the boot of his burnt-out cab in Shek Kong Wai on Christmas Day. A similar amount is on offer in the case of student Lee Wai-hou, 18, who was stabbed to death in Sheung Shui on December 1. The third $300,000 reward is for information about a woman whose body was found in Tsuen Wan two days before Christmas. Officers arrested two men in the taxi case this month and have published a sketch of a third suspect. The two have been released on bail. Xa was last seen working in the Yuen Long area shortly before his car was found on fire at 5pm on December 25. Detectives said they did not rule out the possibility that the driver was killed in a robbery which went wrong. Those with information should contact 2666 4424. Four men aged 22 to 25 are being sought over the killing of Form Seven student Lee who died on a footpath underneath the Pak Wo Road flyover near Sheung Shui police married quarters. Witnesses should call the police on 2666 4432. The third award, also $300,000, was announced on Tuesday for information on the murder of a woman, thought to be a mainlander, whose half-naked body was found on a hillside in Tsuen Wan on December 23. Anyone with information should call 6277 5335. The police said the rewards did not mean they were short of leads. A police spokeswoman said the rewards demonstrated the three homicide cases were being treated by police 'very seriously'. 'We want to get as much information as possible so we can solve the cases and arrest the culprits as soon as possible. It is one of the channels [used by police] to gather information,' she said. The fourth murder was on Christmas Eve when a young mother was stabbed to death on her way home in Yuen Long. Lee Wai, 28, was killed with a single stab wound to the back in the attack outside Yuk Ping House on Long Ping Estate shortly before 1.30am. Although no reward is being offered, police have asked any witnesses to call 6148 1599. Chief Inspector Wong Yiu-wing of the Yuen Long police station said a cash reward would be considered as their last resort and they were still working on all possible clues. On the police reward website, the largest reward is $2 million, in an appeal for information leading to the capture of the killer of a security guard who was gunned down in a bank robbery in Tsuen Wan in 2001.