Gunmen in the northern Nigerian state of Kano killed a policeman and abducted a German citizen on Monday as they travelled to a construction site, police said.

Five gunmen ambushed a vehicle carrying construction workers and opened fire on them along Sabon Titi Madobi road at around 7:45 a.m. (0645 GMT), a police spokesman said. The road is on the outskirts of the state’s capital city, also called Kano.

The vehicle was carrying staff of Dantata & Sawoe Construction Company, a Nigerian firm, to a building site, Kano police said in a statement. A police sergeant, who was part of a protection unit escorting the group, was killed and the German man was abducted, the statement added.

The “manhunt of the abductors is ongoing,” said Kano state police in a statement.

The German embassy in Nigeria declined to comment. The company also did not immediately respond to calls and an email requesting comment.

While the gunmen’s motive is not yet clear, kidnapping for ransom is common in parts of Nigeria.

The abductions were originally targeted at expatriates in the south-eastern oil region of the country but gradually spread to the north of the country, where the authorities increased their crackdown on cattle rustling, which was the most common crime.

Abductees are often released after a few days, once a ransom has been paid.

In January, two Americans and two Canadians on business trips were abducted before being released after a few days in the northern state of Kaduna.

Two South African nationals were also abducted and released a few days later in the same region in late January.

Ten of Nigeria’s 36 states apply the death penalty to abductors.