Officials in northern Nigeria's Kaduna state have imposed a ban on movements following fresh rioting in two cities after a weekend of violence left at least 70 people dead.
The unrest broke out in the cities of Kaduna and Damaturu on Tuesday, adding to fears of rising violence in the country's north, where the Islamist group Boko Haram's campaign has been concentrated.
The Nigerian Red Cross said that at least 25 people were killed in the new attacks in Damaturu.
Twenty civilians were killed in the violence while five security officials reportedly died following attacks on military targets, police said.
"In view of certain new security challenges that came up today ... the state government is hereby re-imposing a 24 hours curfew in all parts of the state," a government statement read.
Suicide blasts claimed by Boko Haram struck three churches in the state on Sunday killing at least 16 people, prompting reprisal violence by Christian mobs who killed dozens more, burning some of their victims.
The latest unrest in the state capital, Kaduna city, started when relatives were unable to reclaim the remains of those killed, according to a resident of Tudun Wada in the city's mainly Muslim northern area.
After some relatives were turned away from a city morgue, protesters "poured into the streets... burning Christian shops and attacking Christians within sight", Habibu Ladan said.
He said soldiers quickly arrived in the area.
Nwakpa O Nwakpa, the Red Cross spokesman, told the AFP that his teams deployed in Kaduna sent "an alert a few minutes ago that there are ongoing protests".
Officials had imposed a round-the-clock curfew when the first rioting began on Sunday.
That curfew was relaxed on Monday afternoon, when the situation appeared to have pacified.