James Ibori has already been acquitted of multiple corruption charges
Police trying to arrest a former state governor in Nigeria charged with corruption have been attacked by his supporters, police say.
Officers were ambushed in Oghara, the hometown of James Ibori in Delta state.
Mr Ibori has been accused of corruption and money laundering while in office by Nigeria's Economic and Financial Crimes Commission (EFCC).
On Tuesday, the inspector general of police ordered the arrest of Mr Ibori within 24 hours.
The police spokesperson told the BBC the attack would not prevent the authorities from carrying out their "constitutional mandate" to arrest Mr Ibori.
On Monday, Mr Ibori's supporters blocked roads leading into Oghara to protest against the EFCC's charges against the ex-governor of the oil-rich state.
This is not the first time the EFCC has tried to prosecute Mr Ibori.
In December 2009, a court in Asaba cleared Mr Ibori of 170 charges of corruption - involving the laundering of millions of dollars - because there was no clear evidence to convict.
The EFCC has been at the centre of a political storm in recent years - dogged by allegations of political bias.