A double bomb attack that killed 31 people in a crowded market in the central Nigerian city of Jos was likely to have been carried out by Boko Haram, the state government said on Friday.

"It's an extension of the terrorist acts that have been penetrating all states and cities," Pam Ayuba, spokesman for the Plateau state governor Jonah Jang, told AFP by telephone.

At least 31 people were killed in a double bombing in the Nigerian city of Jos on Thursday.

Nigerian police arrested a 13-year-old girl wearing an explosives-packed vest in the northern city of Kano hours after an attack by two female suicide bombers, a security source and a witness said Thursday. 

Next year's presidential election in Nigeria will be a repeat of the last vote four years ago, with former military ruler Muhammadu Buhari taking on incumbent Goodluck Jonathan.

Jihadist attacks around the world in November killed a total of 5,042 people, showing Islamist extremism is "stronger than ever" despite al-Qaida's declining role, a new study published on Thursday said.

There were 664 attacks in 14 countries during the month, according to the joint report by the BBC World Service and the International Centre for the Study of Radicalisation (ICSR) at King's College London.

Nigeria's main opposition party on Wednesday began choosing its candidate to run for president next year against incumbent Goodluck Jonathan, who is seeking a second term.

Thousands of delegates from the All Progressives Congress (APC) converged on the country's biggest city and financial hub, Lagos, to vote on which candidate would go forward to challenge Jonathan.

Two female suicide bombers killed at least four people at a busy market in northern Nigeria's largest city Kano on Wednesday, less than two weeks after a horrific attack at the city's central mosque.

Boko Haram has been accused of deploying a wave of female bombers in recent months, including in Kano, and blame for the latest violence will likely fall on the Islamist insurgents.

The Nigerian authorities on Sunday said they had detained a Russian cargo plane carrying military equipment in the north Nigerian city of Kano.

The country's defense chiefs announced on Twitter that the Antonov aircraft was held pending an investigation into its provenance and what it was carrying.

Nigeria on Friday said that a decision to cancel U.S. training of its soldiers to fight Boko Haram was a logistical, not a political decision.

The U.S. Embassy in Abuja announced on Monday that the Nigerian government had halted a training program of an army battalion, which would have developed into a unit to take on the militants.

Boko Haram militants in Nigeria on Thursday stormed a French-owned cement works for the second time in as many months, as they attacked two towns in northeast of the country.

The Islamists first struck in Bajoga, 60 kilometers (40 miles) from Gombe city, in a convoy of 20 vehicles before being pushed to Ashaka, where the plant owned by French group Lafarge is located.