Armed robbers Friday blew up the entrances of five banks in central Nigeria's Offa town with dynamite, in an operation which lasted for more than an hour after the close of business and left six policemen and six civilians dead.
Kwara State police spokesman Ajayi Okasanmi said the police are investigating and working with the bank managers to ascertain how much was carted away, reports BBC.
The incident has drawn widespread condemnation with graphic pictures of killed policemen and residents posted on social media.
The heavily armed gang had attacked the Owode Police Station where they killed the policemen, before raiding the banks within the market area.
Police had recovered some of the vehicles stolen during the raid, Mr Okasanmi said.
Officers were unable to stop the robbers because they were firing sporadically in a densely populated business district, he added.
Robberies like this one have become a regular occurrence in Offa.