The central Nigerian state of Kogi has been placed under a dusk-to-dawn curfew following several sectarian shootings.
Wednesday's curfew announcement comes after gunmen opened fire on a mosque in the town of Okene on Tuesday morning.
That attack came 24 hours after gunmen stormed an evangelical church, cut the electricity and opened fire
once the building was plunged into darkness, killing 19 people on Monday.
"The curfew is imposed in all of Okene, from dusk to dawn," said Jacob Edi, spokesman for the state governor.
On Tuesday in Okene's city centre, assailants shot at troops on patrol, sparking an exchange of fire that left two soldiers and two of the gunmen dead, Simon Ile, Kogi state police spokesman, said.
Motorcycle taxi drivers are also barred from operating in Okene and the state capital Lokoja during night hours, Ile told the AFP news agency, adding that state was calm on Wednesday.
It was not clear who carried out the church killings or whether the two attacks were linked, although Ile said there was "suspicion" that the same group was responsible for both assaults.
HRW new toll
Boko Haram, a radical group, has repeatedly targeted Christians during church worship as well as the security forces.
The group has killed more than 1,400 people since 2010 in attacks across northern and central Nigeria, according to a new toll released on Wednesday by Human Rights Watch.
Boko Haram has said it wants to create an Islamic state in northern Nigeria, but its stated demands have varied widely.
Kogi is further south than the group's usual targets, which are focused in its northeast home base and other
cities across the north.
In February, Boko Haram claimed a prison break in Kogi state when 119 prisoners were freed.
The US state department last month designated three of the group's leaders as global terrorists.
Hillary Clinton, the secretary of state currently on an Africa tour, is expected in the capital Abuja on Thursday for talks in which security concerns are likely to feature prominently.
Nigeria, Africa's most populous nation and largest oil producer, is roughly divided between a mainly Muslim north and predominantly Christian south.