Four local officials from Gansu Province, Northwest China, are being investigated over allegations of graft, the Supreme People's Procuratorate (SPP) said on Wednesday.

Guo Deqing, former top political advisor of Baiyin City; and Ren Wanli, formerly deputy head of a management committee at Lanzhou New Area industrial park, are both suspected of accepting bribes, according to the SPP.

Xu Xiaobiao, former head of the Bank of Communications Gansu branch, is under investigation for alleged corruption, accepting bribes and abuse of power; while Lu Wangcun, former deputy inspector at the Gansu Press and Publication Bureau, was investigated for suspected corruption, accepting bribes and embezzlement.

According to the SPP, all four are now under "coercive measures", which includes summons by force, bail, residential surveillance, detention and arrest. The SPP did not specify what measures had been taken.