LAGOS, Nigeria -- Riot police have been sent to quell fresh outbreaks of religious violence in the northern Nigerian state of Kaduna.
The unrest comes dayss after Kaduna began implementing Islamic sharia law, police said on Monday.
Non-Muslims oppose sharia because of its tough sanctions, including a ban on the sale or consumption of alcohol, amputation of hands for theft and death for convicted adulterers.
Travellers said an undetermined number of people were killed in clashes that erupted in Kaduna's largely Christian southern district of Sanga on Friday, the day sharia law formally came into force in the state.
Reuters reported local media as saying up to 10 people had died.
"The fighting was caused by the legal reforms which began on Friday," Deputy Commissioner of Police Edgar Nanakumo told Reuters.
"The Muslim and Christian youths were fed with conflicting information on the legal reforms. Tempers heightened and boiled over, leading to the crisis," he said.
Police reinforcements sent to the area managed to restore calm, said Nanakumo, who was unable to give a casualty figure.
Street protest Travellers from the area said groups of rival militants set up road blocks in the district and torched cars and buildings.
"We ran straight into the unrest and saw a number of people killed," said a businessman travelling to the commercial city of Lagos.
Attempts to introduce the strict Islamic penal code in Kaduna last year led to two rounds of Christian-Muslim rioting that killed hundreds of people in Kaduna city, the state capital.
Last year's Kaduna riots were triggered by a massive street protest by Christians after the state's legislature began debating plans to introduce the Islamic code.
Kaduna authorities took special care to prevent passions getting out of hand this time, with Friday's event passing almost unnoticed in the state capital.
Tensions have remained generally high in the Sanga area since last year's sectarian clashes, which have been repeated in other major cities in the largely Islamic north of the country.
President Olusegun Obasanjo, whose election in 1999 ended 15 years of military rule in the northwestern African country of over 110 million people, is struggling with the worst cycle of ethnic and religious violence for over 30 years.
Obasanjo maintains that eruptions in different corners of the multi-ethnic country were to be expected after decades of military dictatorship, during which soldiers suppressed grievances among various groups.