Eighteen people were killed in Nigeria after suicide bombers evaded the authorities by dressing as women and wearing explosives disguised as babies.
And in a new attack on Friday, a teenage boy detonated himself in a northeastern market town, killing 10 people and injuring 25 others.
The target of the disguised bombers was the same northeastern town of Chibok from which Boko Haram abducted scores of schoolgirls in April 2014.
Pogu Bitrus, a community leader, said multiple explosions in the town on Wednesday had killed about 18 people - 17 civilians and one soldier.
Colonel Mustapha Ank of the Nigerian army confirmed a hospital worker's discovery that two of the men were wearing hijabs and had disguised the bombs on their backs to look like babies.
Meanwhile, the attack by a teenage boy which killed at least 10 people was a "huge" blast which took place in Gombi town, according to local Red Cross official Maikano Abdullahi.
"I heard a huge explosion coming from the grain section, which is at the edge of the market," said Mustapha Jalo, according to MailOnline.
"Many of us rushed to the scene and we found carnage. People were scattered everywhere.
"I can say over 10 people died in the explosion. I can't give precise number of the injured but there are many."
The rise of Boko Haram
The rise of Boko Haram
1/19 Boko Haram
The leader of the Islamist extremist group Boko Haram Abubakar Shekau delivers a message. Boko Haram has claimed responsibility for the mass killings in the north-east Nigerian town of Baga in a video where he warned the massacre “was just the tip of the iceberg”. As many as 2,000 civilians were killed and 3,700 homes and business were destroyed in the 3 January 2015 attack on the town near Nigeria's border with Cameroon
2/19 Boko Haram
People displaced as a result of Boko Haram attacks in the northeast region of Nigeria, are seen near their tents at a faith-based camp for internally displaced people (IDP) in Yola, Adamawa State. Boko Haram says it is building an Islamic state that will revive the glory days of northern Nigeria's medieval Muslim empires, but for those in its territory life is a litany of killings, kidnappings, hunger and economic collapse
3/19 Boko Haram
Nitsch Eberhard Robert, a German citizen abducted and held hostage by suspected Boko Haram militants, is seen as he arrives at the Yaounde Nsimalen International airport after his release in Yaounde, Cameroon on 21 January 2015
4/19 Boko Haram
Officials of the Nigerian National Emergency Management Agency (NEMA) visit victims of a bomb blast in Gombe at the Specialist Hospital in Gombe. According to local reports at least six people were killed and 11 wounded after a bomb blast in a marketplace in Nigeria's northeastern state of Gombe on 16 January 2015. Islamist militant group Boko Haram has been blamed for a string of recent attacks in the North East of Nigeria
5/19 Boko Haram
People gather at the site of a bomb explosion in a area know to be targeted by the militant group Boko Haram in Kano on 28 November 2014
6/19 Boko Haram
People gather to look at a burnt vehicle following a bomb explosion that rocked the busiest roundabout near the crowded Market in Maiduguri, Borno State on 1 July 2014. A truck exploded in a huge fireball killing at least 15 people in the northeast Nigerian city of Maiduguri, the city repeatedly hit by Boko Haram Islamists
7/19 Boko Haram
President Goodluck Jonathan visits Nigerian Army soldiers fighting Boko Haram
8/19 Boko Haram
Displaced people from Baga listen to Goodluck Jonathan after the Boko Haram killings
9/19 Boko Haram
Nigeria's President Goodluck Jonathan speaking to troops during a visit to Maiduguri, the capital of Borno State; most of the region has been overrun by Boko Haram
10/19 Boko Haram
Members of the Nigerian military patrolling in Maiduguri, North East Nigeria, close to the scene of attacks by Boko Haram
11/19 Boko Haram
Boko Haram’s leader, Abubakar Shekau, appears in a video in which he warns Cameroon it faces the same fate as Nigeria
12/19 Boko Haram
South Africans protest in solidarity against the abduction of hundreds of schoolgirls in Nigeria by the Muslim extremist group Boko Haram and what protesters said was the failure of the Nigerian government and international community to rescue them, during a march to the Nigerian Consulate in Johannesburg
13/19 Boko Haram
Boko Haram militants have seized the town in north-eastern Nigeria that nearly 300 schoolgirls were kidnapped from in April 2014
14/19 Boko Haram
A soldier stands guard in front of burnt buses after an attack in Abuja. Twin blasts at a bus station packed with morning commuters on the outskirts of Nigeria's capital killed dozens of people, in what appeared to be the latest attack by Boko Haram Islamists, April 2014
15/19 Boko Haram
The aftermath of the attack, when Boko Haram fighters in trucks painted in military colours killed 51 people in Konduga in February 2014
16/19 Boko Haram
The leader of Boko Haram, Abubakar Shekau (with papers) in a video grab taken in July 2014
17/19 Boko Haram
Ruins of burnt out houses in the north-eastern settlement of Baga, pictured after Boko Haram attacks in 2013
18/19 Boko Haram
A Boko Haram attack in Nigeria, 2013
19/19 Boko Haram
Abubakar Shekau, Boko Haram’s leader
Both sets of attacks are blamed on Boko Haram Islamic extremists, who have reportedly turned to suicide bombings on soft targets since troops last year forced them out of towns and villages.
Boko Haram, as the group has been dubbed by other Africans and which means "Western education is forbidden", stepped up attacks outside Nigeria over the past year, including in Cameroon, Chad and Niger.
The group has been fighting to overthrow the government since 2009, which it regards as run by non-believers, and create an Islamic state.
The US designated it a terrorist group in 2013 and its current leader, Abubakar Shekau, pledged the allegiance of the group's estimated 9,000 fighters to Isis in March last year.
The six-year insurgency has killed some 20,000 people and driven 2.5 million from their homes.