"NEMA confirms that an hour ago an explosion occurred in Tudun Wada area of Jos. Security personnel moved to the scene as injured are being evacuated," a spokesman for the national emergency management agency (NEMA) said.
Jos sits on the dividing line between Nigeria's mostly Muslim north and largely Christian south and religious and ethnic clashes regularly flare up.
Earlier on Sunday a bomb exploded in the northern town of Kaduna after security officers stopped the vehicle carrying it from approaching a church, witnesses and police said.
At least 16 people were killed but the final death toll is likely to be higher, an emergency agency spokesman said.
No group immediately claimed responsibility for the Kaduna attack, but the apparent targeting of a Christian place of worship will stir memories of a string of deadly assaults by Islamist militants Boko Haram on Christmas Day last year.