The US has launched strikes against militants linked to the Islamic State group (IS) in north-western Nigeria, where militants have sought to establish a foothold.

Camps run by the group in Sokoto state were hit near the border with Niger, the US military said. Casualty numbers are unclear, but both US and Nigerian officials say militants were killed.

US President Donald Trump said the Christmas Day strikes had been “deadly” and labelled the group “terrorist scum”, saying they had been “targeting and viciously killing, primarily, innocent Christians”.

Nigerian Foreign Minister Yusuf Maitama Tuggar told the BBC it was a “joint operation” and had “nothing to do with a particular religion”.

Tuggar said the strikes had been planned “for quite some time” using intelligence provided by Nigeria. He also did not rule out further strikes.

Referencing the timing of strikes – which took place late on Thursday – he said they did not have “anything to do with Christmas”.

The US military said an “initial assessment” suggested “multiple” fatalities in Sokoto state.

A local official in the Tangaza area of Sokoto state, Isa Salihu Bashir, told the BBC the strikes had “hit some Lakurawa terrorist camps”. He said many fighters had been killed but the death toll was unclear.

The BBC has been unable to independently confirm casualty figures.

Bashir added that border patrols on the Niger side reported seeing Lakurawa fighters fleeing the targeted areas.

The Nigerian government has long been fighting an array of jihadist groups, including Boko Haram and IS-linked factions, but largely in the north-east. But in recent years a smaller group – known locally as Lakurawa – has sought to establish a base in north-western Sokoto state.

Nigerian authorities say the group has links to jihadist networks in Mali and Niger. They add that its members have settled in border communities, recruited young people, and imposed harsh controls.

Tangaza is made up of remote villages, whose residents are mostly moderate practising Muslims.

In a statement late on Friday, Nigeria’s information ministry said “precision strike operations” had been carried with the “explicit approval” of President Bola Tinubu and with “the full involvement of the armed forces of Nigeria”.

It also said that during the operation debris from munitions fell in two communities – the village of Jabo, also in Sokoto state, and Offa in Kwara state, about 600km (370 miles) to the south. No civilian casualties were reported in either location.

An eyewitness in Jabo, Umar Jabo told the BBC: “Something that looked like a plane flashed and crashed… in fields.”

He said there was no issue with IS in the area: “We live peacefully, and there is no conflict between us and Christians.”

The Trump administration has previously accused the Nigerian government of failing to protect Christians from jihadist attacks and has claimed a “genocide” is being perpetrated.

Trump has labelled Nigeria a “country of particular concern”, a designation used by the US state department that provides for sanctions against countries “engaged in severe violations of religious freedom”.

The US military was ordered to prepare to intervene in Nigeria in November.

In a social media post late on Christmas Day confirming the strikes, Trump said that he would “not allow Radical Islamic Terrorism to prosper”.

US Defence Secretary Pete Hegseth said on Thursday that he was “grateful for Nigerian government support & cooperation”. The Pentagon later posted a short video that appeared to show a missile being launched from a ship.

Nigeria is Africa’s most populous country, with about 220 million people, divided roughly evenly between Christians and Muslims.

Jihadist groups such as Boko Haram and IS-linked offshoots have wrought havoc in north-eastern Nigeria for more than a decade, killing thousands of people.

Most victims have been Muslims, according to Acled, a group that analyses political violence around the world.

The strikes are the second major US intervention targeting IS in recent weeks.

Last week, the US said it had carried out a “massive strike” against IS in Syria.

US Central Command (Centcom) said fighter jets, attack helicopters and artillery had struck more than 70 targets. Aircraft from Jordan were also involved.

Those strikes were launched in retaliation for the killing of three Americans – two soldiers and a civilian interpreter – in an ambush.