At least 80 people have been killed in Nigeria in a series of attacks blamed on Islamic extremist Boko Haram militants.
In the northeastern city of Maiduguri, capital of Borno state, at least 30 were killed and more than 90 wounded in overnight blasts and shootouts, while another 20 died in a bombing outside a mosque at dawn on Monday, said Muhammed Kanar, area coordinator of the National Emergency Management Agency.
The military said there were also multiple attacks at four southwestern entry points to the city.
In another blast, two girls blew themselves up in the Buraburin neighbourhood, killing several people, according to civil servant Yunusa Abdullahi.
"We are under siege," Abdullahi said. "We don't know how many of these bombs or these female suicide bombers were sneaked into Maiduguri last night."
He said some residents have found undetonated bombs.
Another twin suicide bombing killed at least 30 people in Madagali, a town 150 kilometres southeast of Maiduguri.
Witness Danladi Buba said two women blew themselves up at a market near a busy bus station at about 9am local time.
Brigadier General Victor Ezugwu, the officer commanding in northeast Adamawa State, confirmed the attack but said casualties have yet to be established.
The attacks appear to be a challenge to President Muhammadu Buhari's declaration last week that Boko Haram has been "technically" defeated, capable of no more than suicide bombings on soft targets.
Acting on information provided by a captured insurgent, Nigerian troops "intercepted and destroyed" 13 suicide bombers and arrested one female suicide bomber in repelling the attackers, Major General Lamidi Adeosun, the commander prosecuting Nigeria's war against Boko Haram, told reporters.
Maiduguri, a city of about 1 million people, now hosts almost as many refugees, among 2.5 million people driven from their homes in the 6-year-old Islamic uprising led by Boko Haram.
About 20,000 people have been killed in Nigeria and hundreds others elsewhere as the insurgents have carried their conflict across its borders into Cameroon, Niger and Chad.
