JOS, Nigeria -- Two car bombs exploded at a bustling bus terminal and market in Nigeria's central city of Jos on Tuesday, killing at least 118 people, wounding dozens and leaving bloodied bodies amid the flaming debris.
There was no immediate claim of responsibility for the twin car bombs. But they bore the hallmarks of Boko Haram, the Islamic extremist group that abducted nearly 300 schoolgirls last month and has repeatedly targeted bus stations and other locations where large numbers of people gather in its campaign to impose Islamic law on Nigeria.
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 billows of black smoke.
"It's horrifying, terrible," said Mark Lipdo of the Stefanos Foundation, a Christian charity based in Jos, who described the sickening smell of burning human flesh.
A woman's body, her legs blown off, lay on the edge of an inferno consuming other bodies. In the middle if the flames, an arm reached up. Another woman, unconscious and wrapped in a brightly colored cloth, was being carried away in a wheelbarrow on a road strewn with glass shards.
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.
At least 118 people were killed and dozens wounded in the bombings, which ignited fires that were still burning eight hours later, according to Nigeria's National Emergency Management Agency.
"Firemen are still trying to put them out. We believe we will find more bodies," Mohammed Abdulsalam, zonal coordinator for the agency, told The Associated Press. He said the fires were being fueled by flammable goods at the market, including rubber sandals.
Tensions have been rising between Christians and Muslims in Jos, the capital of Plateau state in Nigeria's Middle Belt region that divides the country into the predominantly Muslim north and Christian south. It is a flashpoint for religious violence, and there were fears the attacks could ignite a new round of sectarian violence.
President Goodluck Jonathan indicated he blamed Boko Haram for Tuesday's bombings, extending sympathies to affected families in a statement and assuring "all Nigerians that the government remains fully committed to winning the war against terror."
"This administration will not be cowed by the atrocities of enemies of human progress and civilization," the statement said.
Boko Haram has claimed other recent attacks, including two separate bomb blasts in April that killed more than 120 people and wounded more than 200 in Abuja, the nation's capital. One went off at Abuja's busy bus station and the other nearby.
A suicide car bomber killed 25 people on Monday in northern Kano city, where police found and disabled a second car bomb before it went off. Authorities said the death toll would have been far higher, but the first bomb exploded before it reached its target of restaurants and bars in the Christian quarter of the Muslim city.
Lipdo said at least one of Tuesday's blasts could have been averted if authorities had acted in time. He said a white van that held the first bomb was parked for hours in the market place, raising suspicions of vendors and others who reported it to the authorities, but nothing was done.
He said authorities also had another warning of impending violence: A man with explosives strapped to his body was arrested on Saturday and told police that many militants had been ordered to plant bombs around churches and public areas in Jos.
The Nigerian government and military's failure to curtail the 5-year-old Islamic uprising, highlighted by the April 15 abduction of at least 276 schoolgirls and lack of progress in rescuing them more than a month later, has caused national and international outrage.
Jonathan has been forced to accept help from several nations including Britain and the United States, in the hunt for the girls, who were kidnapped in northeast Nigeria. 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 a U.N. Security Council committee monitoring sanctions against al-Qaida to add Boko Haram to the list, with an arms embargo and asset freeze.
The extremists are threatening to sell the girls into slavery if Jonathan does not free detained insurgents, which officials say he will not do.
Boko Haram, whose name means "Western education is sinful," has targeted schools, as well as churches, mosques, marketplaces, bus terminals and other spots where large numbers of civilians gather in its campaign to turn Nigeria into an Islamic state. Half of Nigeria's population of 170 million is Christian, as is most of the population of Jos. The militants have increased the reach of their attacks this year, and their deadliness.
On Christmas Eve in 2010, bombs allegedly planted by Boko Haram exploded in Jos, killing as many as 80 people.
Meanwhile, hundreds of people have been killed in assaults on towns and villages in recent weeks, and the extremists also are blamed for an attack last week on a Chinese camp in neighboring Cameroon in which one Cameroonian soldier was killed and 10 Chinese workers abducted.
More than 300 people were killed in a May 5 attack on the town of Gamboru, near the Cameroon border, where insurgents identified by residents as Boko Haram militants razed dozens of homes, more than 1,000 shops and hundreds of vehicles.
Militants' attacks have been coming with increasing frequency despite a year-old military state of emergency in three of Nigeria's states to curtail the uprising.
The Senate on Tuesday voted to extend the emergency for another six months, but only if Jonathan devotes more money to the military campaign and to better arming demoralized soldiers, who say Boko Haram is better equipped. A letter with the conditions was sent to the president.
More than 2,000 people have been killed in the insurgency this year in Africa's most- populous nation, compared to an estimated 3,600 between 2010 and 2013.