Two explosions killed at least 28 worshippers at a mosque in north-eastern Nigeria and wounded at least 56 others, with many of the victims caught in the second blast while trying to flee, police said.

The attack in Mubi town came a day after President Muhammadu Buhari met with US President Donald Trump at the White House and discussed the threat from the Nigeria-based Boko Haram extremist group. Its fighters were quickly blamed for Tuesday’s blasts.

This is the second time in six months that dozens have been killed in an attack on a Mubi mosque. In November, a teenage suicide bomber attacked worshippers as they gathered for morning prayers, killing at least 50 people in one of the region’s deadliest assaults in years.

One resident, Isa Danladi, said he had been about to leave his house near the mosque when he heard the blast.

“The mosque roof was blown off and the prayer was midway when the bomber, who was obviously in the congregation, detonated his explosives,” Mr Danladi said. “This is obviously the work of Boko Haram.”

The National Emergency Management Agency coordinator in Adamawa state, Imam Abbani Garki, said 18 people were critically wounded and had been evacuated for treatment in Yola city.

Haruna Hamman Furo, the head of the state emergency management agency, called the attack “devastating”.

Boko Haram briefly took over Mubi in late 2014 as its fighters rampaged across the region, seizing towns and villages in its quest to establish a hardline Islamic state.

Boko Haram displaced barter to survive Show all 15 1 /15 Boko Haram displaced barter to survive Boko Haram displaced barter to survive Here, Aisha Umaru Gaye holds up a pumpkin that she plans to swap at the Bakasi IDP camp Reuters Boko Haram displaced barter to survive Falmata Ahmadu swaps her bowl of maize for Musa Ali Wala’s amaranth vegetables Reuters Boko Haram displaced barter to survive Mohammed Ali holds up two tomatoes and some dried vegetable leaves Reuters Boko Haram displaced barter to survive Isa Zakariya Audu holds pieces of firewood whilst Kakaye Ahmadu Maikifi holds up a plate of okra Reuters Boko Haram displaced barter to survive Famta Musa Tamaha holds a crate of eggs Reuters Boko Haram displaced barter to survive Zainab Umar gives parboiled soya bean paste to Aisha Jaule in exchange for spaghetti Reuters Boko Haram displaced barter to survive Abachi Mohammed holds six packets of chicken instant noodles Reuters Boko Haram displaced barter to survive Nasiru Buba exchanges detergent for a tray of peanuts Reuters Boko Haram displaced barter to survive Insua Damladi holds up a sachet of salt Reuters Boko Haram displaced barter to survive Falmata Madu exchanges her plate of uncooked rice for Hadisa Adamu’s ground maize Reuters Boko Haram displaced barter to survive Jibril Adamu holds okra seeds and sugared peanuts REUTERS Boko Haram displaced barter to survive Aisha Umaru presents a basin of milk as Umari Usman Kaski holds up firewood Reuters Boko Haram displaced barter to survive Aisha Alhajji Audu holds four small red onions Reuters Boko Haram displaced barter to survive Binta Lawal holds up a bowl of poultry feed with Aisha Buba Reuters Boko Haram displaced barter to survive Abdulwahal Abdulla holds a bowl of dried young tilapia fish Reuters

The military and civilian militia ousted the extremists from the town, which is a commercial hub near the border with Cameroon.

In recent months, Boko Haram activity has been concentrated in the far north of Adamawa state, around Madagali, near the border with Borno state. That area is not far from the Sambisa Forest area where the extremists had a stronghold.