KANO, NIGERIA - Twenty-nine people kidnapped by gunmen two weeks ago as they returned from a wedding in northwest Nigeria have been freed, relatives told AFP on Friday.

The victims, all mobile phone traders, were returning to the Zamfara state capital, Gusau, after attending the wedding of a colleague when one of their vehicles broke down late on June 11.

'Twenty-nine of our members kidnapped two weeks ago were released on Thursday after we paid 20 million naira ($50,000) to their captors,' said Kabiru Garba Mukhtar, the head of the Zamfara mobile traders' union.

The day after the kidnapping, Mukhtar told AFP that 30 guests at the wedding had been kidnapped while 20 others managed to escape.

In fact, 29 people were kidnapped and all were released, he said. 'Their release followed intense negotiations with the bandits who had initially demanded 145 million naira" for the hostages, said Mustapha Halifa, another union official.

After their release, the victims were taken to a hospital to be treated for illnesses contracted because of the 'difficult conditions' of their captivity, Halifa said.

Heavily armed criminal gangs known locally as bandits are rampant in northwest and central Nigeria, attacking villages and carrying out mass kidnappings for ransom despite military operations to combat them.

Gunmen on Wednesday kidnapped 22 farmers from their fields on the outskirts of Nigeria's capital Abuja, the latest in a long line of kidnappings in Africa's most populous country.

The gangs operate for financial reasons with no ideological motive.

But possible alliances with jihadi groups who have waged an insurgency in the northeast for 13 years have raised concerns.