A group of armed youths has just arrived in Gao from Burkina Faso, joining hundreds of other young African recruits who have come to sign up with radical Islamists controlling the northern Mali town.

Dressed in khaki robes, the new batch of youths will join others from Senegal and Ivory Coast milling about in the scorching heat in the courtyard of a building the jihadists have made the headquarters of their Islamic-law-enforcing police.

"We are many Africans, come from all over to join the mujahideen in Gao," says an Ivorian who says he has now taken a new name, Ahmed El Guedir.

In less than two days, over 200 Africans have been conscripted by the Movement for Oneness and Jihad in West Africa (MUJAO), the group said on an exclusive trip under their protection to a region which has been a no-go area for western news organisations since being seized by armed groups in late March.

On average, the recruits are about 16 years old. Some came out of a sense of conviction, some were paid, according to corroborating sources.

"They were promised the sun, moon and stars," said one of these sources on condition of anonymity.

The youths have been separated into two training camps where they will "undergo military and religious training", says the head of the Islamic police, who identifies himself only as Alioune.

"There are more than 200 youths now, we are awaiting many more," he adds.

Gao is one of the key northern cities, along with Kidal and Timbuktu, which were occupied by armed groups in the vast north of Mali after a March 22 coup.

The takeover was spearheaded by separatist Tuareg rebels, but hardline Islamists such as MUJAO and Ansar Dine (Defenders of Faith), who hold Timbuktu, have since chased the Tuareg, a traditionally nomadic ethnic group, out of all key positions.

The jihadists are linked to Al-Qaeda in the Islamic Maghreb (AQIM) and have set about enforcing the strict Islamic law known as sharia. Ansar Dine members have also destroyed ancient Muslim tombs and other World Heritage sites in Timbuktu that they consider idolatrous.

While reports come in from Timbuktu of unmarried couples, smokers and drinkers being whipped, MUJAO has eased its stance on sharia in Gao after angry protests in response to a ban on playing football and watching television.

"MUJAO learned its lesson from the last revolt by the population against them, so they have become more understanding," a teacher says.

The small town near the Niger border has emptied out. Only about 35,000 of its original 70,000 inhabitants remain after residents fled the Islamist takeover.

Overall the UN estimates some 365,000 Malians have been displaced in the crisis.

Those who remain appear resigned to living under their new jihadist leaders, who can be seen driving vehicles carrying their black flag.

Evidence of the fighting during the takeover in March and bloody clashes with the Tuareg rebels in late June can be seen in destroyed and bullet-scarred buildings. All bars and hotels have been closed by the Islamists.

"We are on Muslim land, we are not here to hurt the population," says Abdoul Hakim, the emir of MUJAO in Gao.

Some appear grateful to MUJAO for having chased out the Tuareg rebels (MNLA), accused of committing atrocities in the town, and the Islamists have sweetened their presence with food and financial assistance and by cleaning up the town.

"Look at this gutter, since it was built 15 years ago this is the first time it has been cleaned, and it was the mujahideen who took the initiative," says Ibrahima Toure, a member of a local youth organisation.

Feeling abandoned by the government -- grappling in Bamako for a solution to the northern crises -- many appear to have accepted MUJAO's presence.

"What is the Malian government doing?" says Toure. "Are we still Malian? In Bamako they are fighting like cat and dog while we suffer here."

Another youth, Issa Traore, says: "Our soldiers fled Gao. Today it is the government which has fled its responsibilities and forgotten us completely. It was the Islamists who freed us from the MNLA which was committing atrocities here."

As concern rises that the rebel-held north, an area larger than France, could become a new breeding ground for terrorists, Mali and its international partners are weighing a military intervention to win back their territory.

Bilal Hicham, the first black leader of a "katiba" (fighting unit) and a citizen of Niger -- who says his dream is to "die a martyr" -- scoffs at this, saying: "If someone decided to use force, the force of God will be stronger.

"Here there are Malians, Somalis, Ivorians, Senegalese, Ghanaians, Gambians, Mauritanians, Algerians, Guineans, Nigeriens, all the Muslims are here."

As recruitment efforts are ramped up, MUJAO confirmed that hundreds of fighters from radical Nigerian Islamist group Boko Haram were present in northern Mali.

Hicham says he is prepared to plant bombs in other West African nations "if necessary".

"Jihad must spread throughout west Africa," he says.