The Niger army on Sunday thwarted an attack by Boko Haram jihadists on Diffa, the largest city in the southwest of the country, local residents and a security source told AFP.

The area around Diffa, a city of around 200,000 located near the Nigerian border, has been repeatedly attacked by the jihadist group, which emerged in Nigeria in 2009.

“We heard gunfire, especially heavy weapons, between 4:30 pm and 7:00 pm on the southern side of the city,” Lawan Boukar, a local resident, said on Tuesday.

“It was an audacious infiltratrion attempt by Boko Haram, who were then forced back to the bridge at Doutchi,” he said, referring to a cross-border bridge about 30 kilometres (18 miles) away.

Another resident said the attackers “came over from the Nigerian side in late afternoon, when the

Ramadan fast was about to break — they were obviously hoping to catch our soldiers unawares.”

A security source confirmed the attack but did not give details. The defence ministry, contacted by AFP, said it would release a statement later. The region abutting Nigeria and Chad has repeatedly suffered Boko Haram attacks since 2015.

The Nigerian jihadists have bases hidden in the vast marshlands of Lake Chad, where the borders of Cameroon, Chad, Niger and Nigeria converge.

Chad claims it killed a thousand jihadists and lost 52 of its men, and drove the jihadists out of its territory. In late March, Niger’s defence ministry claimed that a “leading figure” in Boko Haram, Ibrahim Fakoura, had been killed in an operation in the Lake Chad region.

In 2015, heavy fighting broke out between Niger soldiers and Boko Haram fighters around the strategic bridge at Doutchi and near Damasak, a village which the jihadists seized in October 2014.

Damasak was retaken later by the Niger army, backed by Chadian soldiers. (AFP)