WENZHOU, March 25 (Xinhua) -- An unemployed college graduate in east China has been sentenced to five years in prison for demanding 500,000 yuan (62,500 U.S. dollars) from local government officials to prevent him from going on a killing spree.

Twenty-two-year-old Liang Yanhui, a native of Jiangxi Province, was convicted of attempting to blackmail the government of Rui'an City, in Zhejiang Province.

The court was told that Liang went to Rui'an to look for employment after graduating from a Jiangxi college last year, but failed to secure a job after months of searching. He then decided to extort money from the city government.

In early November last year, Liang wrote a letter to the Mayor of Rui'an claiming that he was a migrant worker in the city and demanding compensation of 500,000 yuan (about 62,500 US dollars) because he had encountered discrimination from the locals. He threatened to begin a killing spree in major districts of the cityif his demand was not satisfied.

After mailing the letter, Liang kept sending text messages to a policeman who was only identified by his surname of Yang, asking him to convey his requests and threats to Party and government authorities of Rui'an City, the court was told.

Liang was tracked down eventually and detained by the police forces on Dec. 26, 2006. Liang was also accused of attempting to blackmail the People's Hospital of Rui'an City for 100,000 yuan by claiming one of his relatives had died because of inefficient medical treatment at the hospital and threatening to blow up the hospital.

He was cleared of this charge due to a lack of evidence.

The court ruled that Liang was mentally stable. It is unknown whether Liang will appeal.