LAGOS: Armed robbers killed six police officers as they fled after a raid on a commercial bank at Idi-Iroko, a Nigerian border town with Benin, witnesses said Friday.

"The policemen were shot dead during the robbers' desperate attempt to get away from the scene," Demola Akilo told AFP.

Another witness Funso Ajakaiye said the robbers had sighted the policemen around the area and immediately opened fire on them on Thursday.

The police were not immediately available to confirm the killings.