JOS, Nigeria - Activists said at least 31 people were killed Thursday when twin explosions rocked downtown Jos in central Nigeria in what appears to be the latest attack by Islamic extremists.

The blasts occurred as store owners were shutting their shops and Muslims were preparing for evening prayers.

One blast went off at an outdoor food stand called Mr Bigs and the other at the nearby entrance to the Terminus market in the center of the city, according to witnesses who spoke on condition of anonymity for fear of reprisals.

Soldiers and police said they were ferrying the wounded to hospitals.

Rescue workers had evacuated 31 bodies, and operations were continuing, civil-rights lawyer Ahmed Garba told the Associated Press. Mark Lipdo of the Stefanos Foundation charity said rescue workers also told him at least 31 people were killed and several were injured, some critically.

In May, twin car bombs in Jos' Terminus marketplace killed at least 130.

Those attacks were blamed on Islamic extremists from the Boko Haram group and were seen as an attempt to ignite fighting between Muslims and Christians. Jos is in Nigeria's Middle Belt, where the mainly Muslim north and predominantly Christian south meet and violence between the two groups is commonplace.

There was no immediate claim of responsibility for Thursday's attack, but it bore all of the signs of Boko Haram.