At least 30 people were killed in three attacks by Islamists in northeastern Nigeria, local officials and inhabitants said Wednesday, days ahead of a meeting between President Muhammadu Buhari and Barack Obama.
The three assaults were carried out simultaneously Tuesday in Borno state, the epicentre of Boko Haram 's insurgency, and are part of a surge in Islamist violence since Buhari came to power on May 29.
Boko Haram has killed more than 660 people in a month and a half.
In the deadliest attack on Tuesday afternoon, more than 20 people were killed outside the town of Ngamdu, local legislator Mohammed Sando told AFP.
" Boko Haram gunmen... yesterday set up a barricade on the Damaturu-Maiduguri highway just outside Ngamdu, and attacked motorists. They killed over 20," Sando said.
"They then moved to Ngamdu and began to set houses on fire. Last week they burnt almost half the village in a similar raid," he added.
Haruna Kabil, a bus driver, said a large number of people from Ngamdu fled their homes after the attacks.
"Some houses in Ngamdu were smouldering when I passed this morning. I learned from some passengers I took from Ngamdu that Boko Haram invaded the village in the evening and began burning homes after attacking motorists on the highway. They said that many people were killed on the highway, by the attackers," Kabil told AFP.
Near Baga, which is located northeast of Ngamdu, Boko Haram attacked residents who had decided to return home from state capital Maiduguri, where they had been living since January after fleeing one of the worst Boko Haram massacres in the group's six-year insurgency.
"Yesterday, they chartered a lorry to (take) them to Baga. On reaching Garin-Giwa, which is just four kilometres (2.5 miles) from Baga, they were ambushed by Boko Haram gunmen who opened fire on the vehicle, forcing dozens of men inside to flee into the bush," said Abubakar Gamandi, head of the fishermen's union in Borno state.
"The gunmen however apprehended eight of the passengers and shot them in the head," he added.
In Damasak, Boko Haram assailants set fire to the town and "opened fire on everyone they saw," said local resident Buba Ari.
"We are now going through the burnt area looking for bodies. So far we have covered five."
Damasak was recaptured in March from Boko Haram control by troops from Chad and Niger.
With Chadian troops still stationed in the town, residents had returned, but according to Ari, the soldiers had advised locals to evacuate within three days because they were withdrawing.
"Most of us followed their advice and crossed the border into Diffa," Ari said, explaining that some had returned to pick up personal belongings when the gunmen attacked.
Buhari to Washington
The attacks underline the threat still posed by the Islamists, despite the authorities' pledges to crush Boko Haram 's insurgency.
The group has also carried out suicide attacks in recent days in neighbouring Chad and Cameroon.
Nigeria's Buhari, who was elected on a pledge to crush Boko Haram , is set to travel on Sunday to Washington for a four-day visit, meeting his US counterpart Obama and other top officials on Monday.
The main item on the agenda, according to a statement from the Nigerian presidency, "will be measures to strengthen and intensify bilateral and international cooperation against terrorism in Nigeria and west Africa".