The police confirmed the attack but said the casualty figures could not yet be ascertained.
Some police officers were on Sunday killed when gunmen attacked the convoy of Ifeanyi Ubah, the senator representing Anambra South District in the Nigerian Senate.
The senator's convoy was attacked in Enugwu-Ukwu, a community in Njikoka Local Government Area of Anambra State, Nigeria's south-east.
The gunmen were said to have ambushed and opened fire on the convoy, killing a yet to be confirmed number of police officers attached to the lawmaker.
One source said police officers in the convoy initially engaged the gunmen in a shootout during which three of the officers were killed.
A second narrative said about seven of the officers were gunned down by the hoodlums during the shootout.
The senator, Mr Ubah, reportedly escaped the attack, but sustained injuries.
"Some of his aides were killed, including some police officers. The senator managed to escape as his car was riddled with bullets," a witness said.
"I was driving to that spot from the link road to the express when some people in a shop shouted at me and asked me to turn back and take another route, which I did," the witness added.
There are speculations that what happened was an assassination attempt.
When contacted, the police spokesperson in the state, Tochukwu Ikenga, confirmed the attack on the senator's convoy.
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"Yes. There was an attack at Enugwu-Ukwu today, but the casualty figure is not clear," he said.
Mr Ikenga said the Commissioner of Police in the state, Echeng Echeng, led operatives to the scene of the attack.
He said the details of the attack were still sketchy.
"Police operatives are on ground there as operations are going on. The situation is being monitored," the police spokesperson said.
Mr Ubah is a member of the Young Progressive Party (YPP).
He was a governorship candidate for the YPP in the 2021 governorship election in Anambra State which was won by the incumbent governor, Charles Soludo of All Progressive Grand Alliance.
Anambra, like other states in the South-east, has witnessed several attacks by gunmen.
A state lawmaker was recently kindnapped and subsequently murdered in the state.
The Nigerian government has blamed the attacks on a separatist group, IPOB.
