At least 18 people were killed and dozens of others were wounded in a series of suicide bombings on Saturday afternoon in northeastern Nigeria, including at a wedding and a funeral, according to local officials and the police.

Barkindo Saidu, the director general of Borno State’s emergency management agency, said that three female attackers had struck distinct locations in Gwoza, a bustling city in Borno State that has been the center of Islamist insurgency by Boko Haram over the past 15 years.

The victims included children and pregnant women, Mr. Saidu said. Some Nigerian news outlets reported that at least 30 people had been killed.

As of Sunday morning, no group had claimed responsibility for the bombings. The blasts resembled previous attacks carried out by Boko Haram, whose fighters have killed tens of thousands in Nigeria and whose aggression in the region has led to the displacement of more than two million people.

The first attacker on Saturday detonated a bomb that she was wearing at a wedding celebration, Mr. Saidu said in a preliminary report seen by The New York Times. Eight people died in that explosion, including the attacker and a baby she had with her, according to Kenneth Daso, a public relations officer with the police in Borno. Two attackers struck later near a hospital and at the funeral services of a victim of the earlier blast, Mr. Saidu said.

Nigeria, Africa’s most populous country, has been battling multiple security crises for years, including mass kidnappings of people of all ages and classes.

Boko Haram insurgents have abducted thousands of teenage girls and coerced them into forced marriages. They have also forced many to carry out suicide attacks at schools, markets, religious buildings and large gatherings.

In 2014, Boko Haram fighters kidnapped 276 schoolgirls in the village of Chibok. The Chibok Girls, as they came to be known, received global attention after condemnation by Michelle Obama and because of activism by campaigners who popularized the slogan “Bring Back Our Girls.”

A decade later, dozens are still missing.

Also in 2014, Boko Haram’s leader at the time, Abubakar Shekau, declared a caliphate in Gwoza after his fighters seized the city. The Nigerian Army retook control in 2015, and Mr. Shekau was killed in 2021, but Boko Haram fighters have since staged multiple attacks in the vicinity.