The toll in Tuesday's blast in a livestock market in Nigeria's northeastern city of Maiduguri, capital of the restive Borno State, rose to 31 on Wednesday, hospital sources said.
Many local traders were affected in the bomb blast at Gamboru, a big market in the city, the hospital sources and rescue workers told Xinhua news agency.
Eleven out of the 31 corpses evacuated at the scene of the blast were taken to Borno State Specialists Hospital, a state-run health facility, a medical staffer said, adding that at least 25 others injured were rushed to the hospital.
The state emergency management agency confirmed its rescuers evacuated 31 bodies at the market, after the incident.
While some witnesses said the bomb was buried under a large table used by one of the local traders at the livestock market, others said it was detonated by a suicide bomber who came as a customer.
The bomb exploded while business was thick and immediately killed at least 12 people, a witness named Abba Mohammed said on Tuesday.
Mohammed described the incident as "devastating" and blamed it on the Boko Haram, an Islamist terror group proving to be a hard nut to crack in the most populous African country.
Tuesday's attack came after two previous weekend attacks in Maiduguri, the known headquarters of Boko Haram, since new President Muhammadu Buhari was sworn in last Friday.
During his inaugural speech, Buhari had ordered the relocation of Nigeria's defence headquarters to Maiduguri until the Boko Haram was subdued.
The Nigerian leader will on Wednesday embark on his first official trip to neighbouring countries Niger and Chad to seek and renew their governments' cooperation in ending the security threat posed by the Boko Haram.
