Nigerian security forces have freed two German archaeologists kidnapped by gunmen at a remote dig site.

The two academics were at the German embassy in Abuja on Sunday, and were doing well considering the circumstances, according to the German foreign ministry.

Nasir Ahmad El-Rufai, the governor of northern Kaduna state, commended the security agencies for their efforts in securing the release of the Germans, a statement said. It did not say whether anyone had been arrested for the kidnapping.

Gunmen had been demanding a ransom of 60 million naira (about £150,000) for the release of Prof Peter Breunig, and his assistant, Johannes Behringer, who were abducted at gunpoint on Wednesday and walked into the bush from an archaeological dig near Janjala village in Kaduna state. Two villagers who tried to help the Germans were shot and killed by the kidnappers, the police said.

Breunig, 65, and Behringer, in his 20s, are part of a four-person team from Frankfurt’s Goethe University. The other two members, women, were not touched by the kidnappers. The Germans were collaborating with Nigeria’s national commission for museum and monuments to recover relics of the Nok culture. The early iron age people, considered the earliest ancient civilisation of the west African region that is now Nigeria, are famous for their terracotta sculptures.

Kidnappings for ransom are common in Nigeria, with ordinary residents and even schoolchildren targeted as well as foreigners. Victims are usually released unharmed after a ransom is paid.