Ten people including two police officers have been killed and a number of students abducted in Nigeria's southeast, police said Friday, in a region where separatist tensions are on the rise.

Dozens of security operatives have been killed during attacks by gunmen on checkpoints, police stations and prisons in the region in the past few months. 

On Thursday, gunmen stormed Obosi police station in Anambra state but were engaged in a gunbattle by police officers on duty.

"Two police operatives paid the supreme price," state police spokesman Ikenga Tochukwu said in a statement, adding an investigation was under way to identify the perpetrators.

He said the gunmen also set part of the police station and two vehicles ablaze before fleeing. 

In a separate incident Thursday, a team of police and other security forces repelled an attack on Orlu police station in neighbouring Imo state, police said.

A senior police officer who asked not to be named told AFP that eight gunmen were killed in the shootout.

Southeast Nigeria has seen a surge in deadly attacks targeting police and other security forces in the past few months.

The police have blamed the Indigenous People of Biafra (IPOB), an outlawed separatist movement seeking independence for the Igbo people of the southeast, for some of the attacks. 

But IPOB has denied the charges.

In another incident in the region, the Abia state government said some university students and passengers were kidnapped by unknown gunmen Wednesday on a highway to neighbouring Imo state.

Abia information commissioner John Okiyi Kalu said the students "ran into the armed gang who marched them into the nearby forest along with other yet to be identified travellers".

"Two of the students managed to escape... while others are still being held," he said.

Kidnapping by criminals for ransom is frequent in Nigeria.