The attacks killed at least 26 people and wounded 25 more, a civilian defense fighter who helped evacuate the victims told the Associated Press.
Another witness provided a much higher death toll. "We counted 42 dead bodies outside the mosque," anti-Boko Haram fighter Amadu Marte told Agence France-Presse.
"All the people in the mosque died. Not a single one escaped," said Muhtari Ahmadu, a trader near the site of the blasts, also speaking with AFP.
The first suicide bomber allegedly activated his charge when he entered the Maiduguri mosque on Thursday evening, according to sources at the scene. The second set off his bomb after people rushed to the scene to help the first victims.
"When rescuers and sympathizers gathered in front of the place, the second one went off, killing many of them," Marte said.
Body parts littered the rubble, according to other witnesses.
Obama sending troops
There was no immediate claim of responsibility for the attacks. However, local residents suspect Islamic insurgents from Boko Haram, the terrorist group founded in Maiduguri in 2009.
The group has since mounted an insurgency that has killed more than 20,000 people, primarily in the restive northeast region of Nigeria but also in neighboring countries including Chad and Cameroon.
Seven people were killed in a separate bombing on Wednesday in Maiduguri.
On Wednesday, US President Barack Obama announced that he will send 300 American soldiers to Cameroon to aid the fight against the terrorist organization.
dj/cmk (AFP, dpa, AP)