Police in the west African nation of Niger have extended by 48 hours the detention of an editor of a weekly magazine held for allegedly defaming a government minister, his colleague said on Saturday.

Zakari Alzouma, editor of Opinion magazine, had questioned the role of Interior Minister Albade Abouba over transport arrangements for Muslim pilgrims to Mecca, resulting in his arrest on Thursday.

Under the country`s laws a suspect can be held for 48 hours before being produced in court, which can then free him or remand him in custody pending trial.

`The initial period of two days in custody expired on Friday, but was extended by two days until Sunday,` the magazine`s editor-in-chief, Ayouba Karimou told AFP.

A police source said such extensions are legal and are applied when investigations are yet to be finalised.

In the article, the journalist accuses the interior minister of having `taken advantage of the absence` of Prime Minister Seini Oumarou, to re-assign a transportation contract to a private US company when it had already been granted to a local operator.

Boubacar Diallo of the Association of Independent Press Editors of Niger on Saturday hit out at the detention extension.

`We are shocked and outraged at the insistence of the authorities to place journalists behind bars,` said Diallo.