Nigeria and its regional allies on Wednesday called for greater international support to shut down Boko Haram's weapons and funding supply as concern mounted at the group's rapid recent land grab.

The call came after conflicting reports that the militants had seized another town, prompting warnings that Nigeria was losing control of the northeast and violence could spill across borders.

With the world's highest birth rate in a country where first-time mothers are often barely past puberty, having a baby in impoverished Niger can be tantamount to a death sentence.

The West African state and humanitarian groups have worked to slash both birth and maternal mortality rates, but despite strides results are not good enough, the UN warned this week.

Dozens of opposition members have been arrested in Niger suspected of plotting a "military coup" in the west African nation, Interior Minister Hassoumi Massaoudou told Agence France Presse on Saturday.

Close to 40 allies of parliament speaker Hama Amadou were detained this week for allegedly planning "a campaign of terror", Massaoudou said, charging that some were found with petrol bombs in their possession.

Two days of student riots in the capital of the west African state of Niger have left at least 10 people injured and several dozen vehicles trashed, Niamey's governor has said.

The clashes in Niamey on Tuesday and Wednesday pitted police using tear gas against hundreds of students angry at delays in the payment of their grants, and armed with stones and hunks of wood.

Security forces from Algeria and Niger are searching for dozens of illegal migrants who went missing in the vast desert between the two countries, an Algerian lawmaker told Agence France Presse Sunday.

"Some people, Africans, are lost in the desert and the security services of both countries, Algeria and Niger, are searching for them," said Mohamed Guemama, an MP with the ruling National Liberation Front.

Slain strongman Moammar Gadhafi's son Saadi has asked Libyans for forgiveness in an interview released by prison authorities three weeks after his extradition from neighboring Niger.

The videotaped interview, which was aired by state television late Thursday, was filmed by warders at the capital's al-Hadba prison, where Saadi and several other Gadhafi regime figures are being held, with the blessing of the chief prosecutor, the broadcaster said.

Human Rights Watch urged Niger to explain its decision to extradite a son of late Libyan dictator Moammar Gadhafi on Thursday.

"The authorities in Niger should explain why they were convinced that Saadi Gadhafi would not be mistreated and would get a fair trial," said Sarah Leah Whitson, HRW's Middle East and North Africa director.

A son of late dictator Moammar Gadhafi was extradited Thursday from Niger to Libya, where he is accused of murder and repression during the 2011 uprising that ended his father's rule.

"Saadi Gadhafi was handed over to the Libyan government on March 6. He has arrived in the country and is in the custody of the judiciary's police," a government statement said.

Nigerian intelligence agents seized the passport of ousted central bank boss Lamido Sanusi when he landed at Lagos airport, Nasir el Rufai, a close Sanusi ally told Agence France Presse Friday.

Rufai, a former cabinet minister who is now a prominent opposition politician, said he was at the airport to meet Sanusi when his flight from Niger's capital Niamey landed at 2:30 pm (13:30 GMT) on Thursday.

Niger on Friday handed over to Libya slain dictator Moammar Gadhafi's former chief of internal security Abdullah Mansur, the Libyan government announced.

A government statement said Tripoli had given the authorities in Niamey evidence implicating Mansur "in planning terrorist acts aimed at destabilizing Libya".