Nigerian police have detained two journalists from a programme that repeated conspiracy theories about polio vaccinations days before deadly attacks on polio clinics, a radio station said Tuesday.

Gunmen attacked two polio clinics in the northern city of Kano on February 8, killing at least 10 people, after Wazobia FM broadcast a story reviving claims that the vaccinations are part of Western plot to harm Muslims.

Wazobia's station chief Sanusi Bello Kankarofi told AFP that a presenter and a reporter are being held by Kano police, along with a source featured on their show.

A third journalist, the station's head of content, was questioned overnight Sunday but has been released, Kankarofi said.

"I received a letter from the police commissioner on Sunday directing me to present" several journalists for questioning, he said. "Two of our staff are still being detained."

Kano's police chief Ibrahim Idris has declined to confirm that the journalists are in detention. He said Monday that investigations into the shooting are ongoing and that several people were being held.

Claims that polio vaccinations are used to render Muslims infertile have long spread in Nigeria's mainly Muslim north, often stoked by local politicians and clerics, dealing setbacks to efforts to eradicate the crippling disease.

Such conspiracy theories led to the suspension of vaccination campaigns in Kano in 2003.

Nigeria is one of only three countries still considered to have endemic polio, along with Pakistan and Afghanistan.

Wazobia's popular Sandar Girma programme, known for being provocative often at the expense of sourced reporting, focused on a man who was allegedly forced to submit his children to vaccinations by district officials.

The father in question is among those being held, according to the Wazobia station chief.

The programme accused health officials of taking money from the West to conduct the harmful vaccinations.

It is not yet clear who was responsible for the February 8 attacks and there was no evidence linking Wazobia's piece to the violence.

Islamist extremist group Boko Haram has carried out attacks in Kano, though gangs linked to local politics also operate.

According to the World Health Organisation, Nigeria accounted for 121 of the world's 222 polio cases in 2012.