A Syrian engineer who was abducted last week by unknown gunmen in Sokoto state in northern Nigeria has been released, the police said on Wednesday.
Abdul Nasir was kidnapped on May 16 on his way to a road construction site outside the state capital of Sokoto city by armed men who killed three policemen that tried to rescue him.
"Abdul Nasir was released on Tuesday at about 12:30 am (1130 GMT) by his abductors," said Sokoto state police spokeswoman Cordelia Nwawe.
"He was dropped off along Arkilla Road on the outskirts of the city".
Nwawe declined to give further details but said no ransom was paid.
Kidnapping has not been common in Sokoto but cattle rustling and kidnapping gangs operate in neighbouring Zamfara state to the west, which has prompted the deployment of troops.
Last week, residents in the Birnin Gwari area of Kaduna state, which also borders Zamfara, said that about a hundred people had been kidnapped along one road in just two days.
On Wednesday, the NURTW road transport union said a further 42 people were seized in the same spot in the last 24 hours and advised members not travel there until security is improved.
In March 2011 a British construction engineer and his Italian colleague were kidnapped from their lodgings in Kebbi state, which borders Sokoto to the east.
It later emerged that Boko Haram splinter group Ansaru was behind the abduction.
The hostages were killed in a botched rescue operation involving British and Nigerian forces in a house in Sokoto where they were kept for 10 months.