At least one bomb has exploded near a market in the northern Nigerian city of Kano, officials and residents say.
A blast hit a vehicle loading area at the Kantin Kwari textile market. Boko Haram militants are suspected of carrying out the attack.
Eyewitnesses said the market was hit by two blasts. At least seven people died and 30 were hurt, hospital sources say.
Last month more than 100 people died in a gun and bomb attack during prayers at one of the biggest mosques in Kano.
Some 2,000 people have been killed in attacks blamed on Boko Haram Islamist militants so far this year.
Two female suicide bombers were responsible for Wednesday's attack, a senior police official told Reuters news agency.
Police spokesman Musa Magaji Majia told reporters that officers were heading to the scene of the blast.
Trader Nura Sadiq told AFP news agency: "I heard a huge sound coming from the back of my shop along Unity Road. I just closed the shop and tried to leave because it's not safe."
Kantin Kwari is the biggest textile market in Kano, where people from neighbouring states and other parts of the country come for transactions, the BBC's Habiba Adamu reports from the capital Abuja.
The market is always jam-packed with people, our correspondent adds.
On 28 November, more than 100 people were killed in an attack on the Central Mosque in Kano.
No group said it had carried out the attack but officials said it bore the hallmarks of Boko Haram.
The Sunni Islamist group has been waging an insurgency in Nigeria since 2009.