Two car bombs exploded at a bustling bus terminal and market in Nigeria's central city of Jos on Tuesday, killing at least 46 people and wounding dozens, police said.
There was no immediate claim of responsibility for the twin car bombs, but they bore the hallmarks of Boko Haram, an Islamic extremist group that is threatening to sell nearly 300 abducted schoolgirls into slavery.
The second blast came half an hour after the first, killing some of the rescue workers who had rushed to the scene, which was obscured by billowing black smoke.
Dozens of bodies and body parts were covered in grain that had been loaded in the second car bomb, witnesses said. A Terminus Market official said he helped remove 50 casualties, most of them dead. He spoke on condition of anonymity because he is not allowed to give information to reporters.
"It's horrifying, terrible," said Mark Lipdo of the Stefanos Foundation, a Christian charity based in Jos, who could smell burning human flesh.
At least 46 people were killed, according to Superintendent Felicia Anslem Ali, police spokeswoman for Plateau state.
Photographs showed a woman's body, legs blown off, on the edge of an inferno consuming other bodies, with a hand reaching out of the flames. Another woman, unconscious, was being carried away in a wheelbarrow on a road strewn with glass shards.
The girls were seized more than a month ago from a remote town in the northeast that is the traditional stronghold of the Islamic extremists who want to turn Nigeria into an Islamic state under Shariah law. Half of Nigeria's population of 170 million is Christian. But they have increased the reach of their attacks this year, and their deadliness.
Two separate bomb blasts in April killed more than 120 people and wounded more than 200 in Abuja, the capital in the centre of the country.
A suicide car bomber killed 25 people in northern Kano city on Monday. Police there detonated a second car bomb Monday. They said both would have killed many people but the first exploded before it reached its target of restaurants and bars in the Christian quarter of the Muslim city.
On Christmas Eve in 2010, bombs allegedly planted by Boko Haram exploded in Jos, killing as many as 80 people. The city known for its gentle climate amid the tropics is in Nigeria's middle belt region in Plateau state, which divides the country into the predominantly Muslim north and Christian south.

More than 300 killed in recent weeks

More than 300 people have been killed in assaults on towns and villages in recent weeks, and the extremists also are blamed for an attack on a Chinese camp in neighbouring Cameroon in which one Cameroonian soldier was killed and 10 Chinese workers abducted.
The official News Agency of Nigeria quoted Maj. Gen. Dave Enebe confirming the two explosions Tuesday in Jos, but saying it was too early to give casualty figures.
Militants' attacks have been coming with increasing frequency despite a year-old military state of emergency to curtail the uprising.
The senate on Tuesday voted to extend the emergency for another six months but only if President Goodluck Jonathan devotes more money to the military campaign and to conditions and arming of demoralized soldiers who say Boko Haram is better armed.
National and then international outrage has erupted over the mass abduction of the girls and the military's failure to rescue them, forcing Jonathan to accept help from several nations including Britain and the United States in the hunt for the girls. It also has brought massive attention to the shadowy extremist group, which is demanding the release of detained insurgents in exchange for the girls — a swap officials say the government will not consider.
Diplomats said Nigeria on Tuesday asked the UN Security Council committee monitoring sanctions against al-Qaeda to add Boko Haram to the list, with an arms embargo and asset freeze.
More than 2,000 people have been killed in the insurgency this year, compared with an estimated 3,600 between 2010 and 2013.