ABUJA (Reuters) - Nigerian police and Shi’ite Muslim protesters clashed in the capital Abuja on Monday, with at least one demonstrator, one journalist and a senior policeman killed, highlighting one of the security challenges faced by the country with Africa’s biggest economy.

A police officer walks past a photographer after the Shi'ite group set an ambulance and a fire engine on fire at the Federal Secretariat in Abuja, Nigeria July 22, 2019. REUTERS/Afolabi Sotunde

A youth leader who was among the Islamic Movement of Nigeria (IMN) protesters said he saw six dead bodies, while a Reuters correspondent in Abuja spotted one corpse, vehicles ablaze and bloodstains along a main street following bursts of gunfire.

Police said a senior officer was killed and three other policemen were injured during the protest, and police had arrested 54 suspects who would be brought to court.

A reporter died after being shot during the rally, international organization the Committee to Protect Journalists Africa tweeted. The local television station, Channels TV, confirmed the tweet.

A spokesman for Islamic Movement in Nigeria said 11 people were killed and at least 30 others injured. He said the police attacked a peaceful march in the capital Abuja, where they were marching to demand for their leader Ibrahim Zakzaky to be freed.

Ibrahim Musa, president of the Media forum of the Islamic Movement in Nigeria, said in a statement that trouble started when the police prevented the group who are on a peaceful protest from accessing their way in Abuja.

The clashes in Abuja’s business district, which lasted for about an hour, underscored the security problems in Africa’s top oil producer and most populous nation - a country that is central to regional stability.

In recent days, bandits in the northwest killed at least 37 people, Islamist insurgents are suspected to have kidnapped aid workers in the northeast and pirates abducted Turkish sailors in the Gulf of Guinea.

IMN members regularly take to the streets of Abuja to call for the release of Zakzaky, who has been in detention since 2015. They say Zakzaky requires medical help. Live ammunition and teargas have reportedly been used by security forces in recent weeks.

IMN youth leader Abdullahi Muhammed said he saw more than 20 casualties in Abuja on Monday, including people who had been shot in their legs and stomach. “I have seen six corpses,” he said, adding that police had taken away many of the bodies.

He said the protest began as a peaceful march but police “started shooting with live ammunition at us”.

Nigerian broadcasting company Channels TV said in a tweet that one of its reporters was shot in the stomach.

The National Emergency Management Agency (NEMA) said IMN protesters set two of its vehicles on fire.

In a statement, Amnesty International called on the Nigerian authorities to investigate the incident and bring to justice those responsible.

‘SECURITY FOR EVERY CITIZEN’

The inspector general of police said he had briefed President Muhammadu Buhari on the situation.

“The president asked us to make sure we provide security for every citizen of this country and not to leave any space that some group of people will create breakdown of law and order,” he told reporters in Abuja.

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Clashes between police and Zakzaky’s backers have raised fears that IMN might turn to violent insurgency as did Sunni Islamist group Boko Haram after police killed their leader in 2009.

Zakzaky has been held in detention since December 2015, when the army killed roughly 350 of his followers at his compound and a nearby mosque and burial ground in northern Kaduna state.

Zakzaky faces trial on charges of murder, culpable homicide, unlawful assembly, disruption of public peace and other offences following the 2015 violence. He has pleaded not guilty.

Buhari, a former military ruler, began a second four-year term in May after winning re-election in February following a campaign in which he vowed to improve security nationwide. He has repeated that pledge in the last few days.

The presidency, in a statement on Friday, urged IMN members to cease their protests on the grounds that the matter was being dealt with in the legal system and not the government.