BAUCHI, Nigeria -- A suicide bomber killed six people Sunday at a church in Potiskum, a city in northeastern Nigeria hit by suspected Boko Haram attacks in the past, a Red Cross official and a witness said. “People were just going to the church when the bomber entered; otherwise the casualty figure would have been higher,” said Red Cross official Hassan Alhaji Muhammad, who visited the scene of the blast on the outskirts of Potiskum.

A hospital in Potiskum said it had received the bodies.

Suspected Islamist militant gunmen and bombers killed more than 200 people last week in a spate of bloodletting that prompted renewed outrage and calls for an international meeting to coordinate the offensive against Boko Haram.

French President Francois Hollande said the Boko Haram threat was getting stronger and that he was ready to hold a summit, following one in Paris in May 2014, to gather the leaders of countries fighting the insurgents.

Recently elected Nigerian President Muhammadu Buhari is due to visit his counterpart in Cameroon after the Muslim holy month of Ramadan and to meet U.S. President Barack Obama July 20, when the fight against Boko Haram is likely to be high on the agenda.

Potiskum is in Yobe state next to Borno, a remote state that is Boko Haram's stronghold in Nigeria and borders Cameroon, Chad and Niger.

(Reporting by Ardo Abdallah; Editing by David Clarke and Janet Lawrence)