MAIDUGURI, Nigeria (Reuters) - Two separate attacks by suspected Boko Haram suicide bombers - one by a female duo, the other by three men - have killed three people in northeast Nigeria, police said on Monday. All the attackers died.

The bombings late on Sunday in Maiduguri, the capital of Borno state where the Boko Haram insurgency began, followed a bloody clash on Saturday in which five soldiers and more than 15 jihadist fighters died in neighboring Yobe state.

The violence marks a resurgence in attacks weeks after President Muhammadu Buhari said Boko Haram fighters had been pushed out of their last stronghold in the northeast where they have been trying to set up an Islamic state.

Maiduguri police said the women bombers claimed two victims there late on Sunday evening shortly after the male group had killed one person in the city. Nobody has claimed responsibility for the attacks but they bear the hallmarks of the group.

The deaths in Yobe state came in Boko Haram attack on an army base in the remote town of Buni Yadi.

The frequency of attacks had slowed down in the last few months, but security analysts say the spate of bombings in the last few weeks has coincided with the end of the rainy season, when movements in the bush are limited.

A man claiming to be Boko Haram leader Abubakar Shekau has appeared in a video denying Buhari’s statement that the group had been pushed out of the region.

Boko Haram’s seven-year-old insurgency, which is aimed at creating an Islamic state in the northeast of Africa’s most populous nation, has killed about 15,000 people and displaced more than 2 million people.

In early 2015, Boko Haram controlled an area about the size of Belgium. It has been pushed out of most of that territory over the past year by Nigeria’s army and troops from neighboring countries, moving to a base in the Sambisa forest, a vast former game reserve in Borno state.

Security analysts say the group’s ability to carry out attacks in neighboring Niger, Cameroon and Chad suggests it has multiple bases.