BEIJING, Aug. 22 -- Investigations into three former officials from northeast China's Heilongjiang Province for bribery have been opened, the Supreme People's Procuratorate (SPP) said Friday.

The officials were Wang Jun, former political advisor of Suihua city in Heilongjiang, Li Guojun, former head of Heilongjiang Institute of Agricultural Mechanical Engineering Science, and Zhang Hou, former president of state-owned Heilongjiang Construction Group Co. Ltd, said in a SPP statement.

They have been "placed under coercive measures," the statement said.

According to China's criminal procedure law, coercive measures include summons by force, bail, residential surveillance, detention and arrest. The SPP did not specify which measures have been taken so far.