Three Nigerian journalists have been arrested for inciting violence by saying on a radio show that polio immunizations were an anti-Islam Western conspiracy, just days before health workers administering the vaccines were killed.
Gunmen on motorbikes shot dead the nine health workers in two separate attacks in Nigeria's main northern city of Kano on Friday.
No one claimed responsibility but Islamist militant group Boko Haram, a sect that has condemned the use of Western education, has been blamed for carrying out a spate of assaults on security forces in the city.
Kano Police Chief Ibrahim Idris told Reuters on Monday three journalists from Wazobia FM had been detained after they said on their show on Wednesday that immunization against polio was anti-Islam and a Western conspiracy to cause infertility in women.
Some influential Muslim leaders in Kano openly oppose the vaccinations for the same reasons.
The killings could hamper efforts by global health organizations to clear Nigeria's mostly Muslim north of the virus that can cause irreversible paralysis within hours of infection.