Unknown gunmen shot dead four policemen Thursday on a police checkpoint near the home of Nigeria’s police chief in the northern city of Kano

Unknown gunmen shot dead four policemen Thursday on a police checkpoint near the home of Nigeria's police chief in the northern city of Kano, a police source and a medic said.
  
A hospital source said four bodies of men in police uniform were taken to a hospital morgue after the attack.

The attack occurred a few hundred meters (yards) from the private home of Muhammad Abubakar, who was appointed Nigeria's new police chief last month.
  
Police did not speculate on the identity of the Thursday attackers, but said 15 suspects were arrested after the assault.