At least 34 people have been killed in coordinated attacks by suspected Islamist militants on several villages in north-western Nigeria, officials have told the BBC.

The gunmen launched simultaneous assaults on multiple communities in a remote border district of Kebbi state on Tuesday, overwhelming local defences and forcing residents to flee their homes.

Survivors described the attackers as highly organised, saying they swept through villages firing indiscriminately at residents.

Officials have blamed the relatively new insurgent group Lakurawa, which is known to operate in the area. It was targeted by US air strikes in December, further north, in Sokoto state.

Security forces have now moved into the area to protect communities and assist survivors. Tracking operations are underway to cut off the militants' escape routes.

Authorities are yet to officially comment on the attacks, although images of shrouded corpses being prepared for burial have been circulating on social media.

The attack has sparked outrage among Nigerians online, with many calling on the government to end the violence that has become all too common in parts of the country.

Nigerian authorities officially declared Lakurawa a terrorist organisation last year and banned it across the country after reports emerged that its fighters were flogging people for listening to music.

Officials say Lakurawa is affiliated with jihadist factions in Mali and Niger. Its militants have for years settled in communities along the Nigeria-Niger border, marrying local women and recruiting young people into their ranks.

The group has previously carried out similar raids in Kebbi, using coordinated simultaneous attacks to swamp local defences.

The emergence of Lakurawa adds to Nigeria's already complex security challenges, as the government continues to battle multiple armed groups, from Boko Haram Islamists in the north-east to heavily armed kidnapping gangs operating across the north-west and central states and separatists in the south-east.