Eleven people were killed on Wednesday when two girls blew themselves up in twin attacks in northern Cameroon, a region repeatedly targeted by Nigeria-based Boko Haram jihadists.

The assault is the second of its kind in the area in the past 10 days, despite a major regional offensive against the Boko Haram insurgents which still poses a major security threat as it steps up its attacks in the restive Lake Chad region.

The girls, who were "under 15", attacked the central market of the regional capital Maroua as well as the adjoining Hausa neighbourhood, regional governor Midjiyawa Bakari said.

In a statement, the presidency said that 11 people had died and 32 were wounded in what it called "cowardly and despicable" acts against innocent civilians.

President Paul Biya urged the security forces to work closely together in order to overcome the jihadist threat, and called on Cameroonians to be "vigilant".

There was no immediate claim of responsibility, but Boko Haram Islamists have carried out a string of deadly assaults, including through female suicide bombers, in their six-year-old insurgency in Nigeria.

The group has abducted thousands of people, including hundreds of women and girls, in the past two years, rights groups say.

A source close to local authorities said "two girls who were begging blew themselves up" at around 3:00 pm (1400 GMT).

A Cameroonian journalist in the town described the "total panic" after the bombings.

"There were mutilated bodies, pieces of flesh on the ground, it's terrible... People have never seen anything like this before here in Maroua," the journalist said, adding that several of the wounded were in critical condition.

In a statement, France's foreign ministry expressed its solidarity with Cameroon, and pledged Paris would support the west African nation's "efforts in the fight against terrorism, along with the states in the region."

Wednesday's was the second suicide attack in 10 days in northern Cameroon, which is located near Lake Chad.

On July 12, two female suicide bombers wearing the full Islamic veil blew themselves up in Fotokol, on the border with Nigeria, killing 10 civilians and a soldier from neighbouring Chad.

Regional authorities have since banned the use of full-face veils.

- Fear, mistrust -

Over the past two years Boko Haram has carried out several cross-border raids and abductions in northern Cameroon but the country, which is engaged in a regional fightback against the jihadists, had previously been spared from suicide attacks.

Once a bustling market town, Maroua now lives in fear and under tight military surveillance. Motorbike traffic is banned in the town after dark, as jihadists are known to use two-wheelers to move around.
According to security sources Maroua has been infiltrated by members and sympathisers of Boko Haram, who have been known to report back to their chiefs with information on the town.

"We don't trust anyone. They are people just like you and me. (A jihadist) could be a taxi driver or a passerby, it is almost impossible to spot them," a Cameroonian officer said.

A regional coalition, which has also drawn in Nigeria, Niger and Chad, has succeeded in retaking several towns and villages in northeast Nigeria from the insurgents.

Their response in recent weeks, since President Muhammadu Buhari came to power in Nigeria vowing to defeat them, has been to step up their attacks, showing they are far from vanquished.

On Wednesday, while on his first visit to Washington since his March election, Buhari warned that a US refusal to arm his troops because of "so-called human rights violations" only helps Boko Haram.

The US government has vowed to help Nigeria defeat the insurgency but it is prohibited under law from sending weapons to countries that fail to tackle human rights abuses.

Cameroon's neighbours have also suffered from Boko Haram's violence in recent days. On July 11, a suicide attack on the main market in Chad's capital N'Djamena left 15 dead and 80 injured.

Boko Haram's deadly insurgency has killed at least 15,000 people since 2009 and left more than 1.5 million homeless.