KADUNA, Nigeria - Muslims youths fired AK-47 rifles, burned tyres and destroyed at least one church in the northern city of Kaduna on Tuesday, two days after rioting by Christian youths killed 52 people, witnesses said.
An explosion also struck a market in Kaduna, residents said, during the latest of a series of retaliatory confrontations between followers of the two faiths in Nigeria.
The escalating violence has raised fears of wider sectarian conflict in a country already reeling from months of attacks on government buildings and churches by followers of the Islamist sect Boko Haram.
The movement styled on the Taliban appears bent on provoking Christian-Muslim clashes as part of its campaign to carve an Islamic state out of parts of Nigeria.
"They (the Muslims) are out on the streets, burning tyres and shooting. They burned a church," said one witness in Kaduna, who only gave his first name, Suleiman, for fear of reprisals.
It was not immediately clear if the shots were fired into the air or at people and other targets.
Religiously mixed Kaduna is near the volatile "Middle Belt", where the mostly Christian south and largely Muslim north meet. The city has been a flashpoint for tensions over religion, ethnicity and land ownership.
The protests in Kaduna followed attacks on Sunday by angry Christian youths who set up roadblocks, dragged Muslims from their vehicles and killed them, according to witnesses.
The Christian youths were in turn reacting to suicide bombings at three churches in Kaduna state, blamed on Islamists, that killed 19 people.
Kaduna Police commissioner Mohammed Abubakar told journalists later on Tuesday calm had been restored and nine suspects arrested.
Officers had also recovered 15 home made bombs, several rifles and pistols with rounds of ammunition, he added.
"We call on the people of Kaduna state to remain peaceful to ensure the maintenance of law and order," Abubakar said.
Kaduna authorities imposed a second 24-hour curfew in two days.
ISLAMISTS, SECURITY FORCES BATTLE
Hundreds of kilometres away in the northeastern city of Damaturu, at least three policeman and two soldiers were killed in overnight clashes with Boko Haram suspects.
Yobe State commissioner of police, Patrick Egbuniwe, confirmed the deaths to reporters and said sect members and civilians were also killed. He could not confirm how many because they were still collecting bodies.
The Yobe state government has also imposed a 24-hour curfew.
In November, 65 people were killed in attacks claimed by Boko Haram on churches, mosques and police stations in Damaturu, where security forces often clash with Islamists in gun battles.
Sensitive to the possibility of religious tensions escalating, the Senate appealed for unity.
"The senate agrees that there is an attempt to pitch each religion against the other but we are appealing to Nigerians not to fall for the trap," Nigeria's Senate spokesman Eyinnaya Abaribe said after a meeting of the lawmakers on Tuesday.
Riots killed hundreds in the city in April last year after President Goodluck Jonathan, a southern Christian, defeated northern Muslim Muhammadu Buhari in elections.
Boko Haram's leader Abubakar Shekau has said the attacks on Christians were revenge for past killing of Muslims.
Jonathan has been criticised for failing to end the attacks.
"Since these terrorist acts began, nothing the President has done has been re-assuring that the end to this spate of bombings and gun attacks is in sight," a statement from the Christian Association of Nigeria said on Tuesday.
"His utterances after each bombing and killing ... seem to have cast a hallmark of weakness on his presidency."