The Democratic Republic of Congo's army says an Islamist militia was responsible for two blasts in the eastern city of Beni as the mayor closed schools, churches and markets for 48 hours.
The army said Sunday's attacks bore the signature of the Allied Democratic Forces (ADF), which has used improvised explosive devices in the past.
The ADF, which originally hails from Uganda, has been accused of killing thousands of people since 2014, most in massacres in remote villages carried out with machetes, hatchets and firearms.
On Sunday, the first explosive device injured two people at a Catholic church.
Later a suspected bomber was killed when the device he was carrying detonated prematurely at a busy intersection, authorities said.
No one else was reported killed.
The army said the bomber was a Ugandan citizen.
"We have arrested two suspects who were with the bomber and it is thanks to them that we have been able to identify him," said Anthony Mualushay, an army spokesman.
The army's statement coincided with the publication of a claim by Islamic State group that it had carried out the attacks.
It said they killed two people.
It was not possible to independently verify the assertion, made through a verified IS-related Telegram channel.
IS has claimed dozens of killings blamed on the ADF in the last three years, although UN experts say they have not found conclusive evidence IS has control over ADF operations.
UN and independent experts have also cautioned that some attacks blamed on the ADF have, in fact, been carried out by other militias or by factions of the DR Congolese army.