Nigeria's Boko Haram Islamist militants appear to be gaining strength and firepower from an alliance with al-Qaida in North Africa amid reports dozen of them are in Mali with Tuareg rebels while weapons looted in Libya have turned up in Nigeria.

The emergence of Islamic extremists from Nigeria, where the government is battling a surge of attacks by Boko Haram, in turbulence-torn North Africa, if correct, would mark a tightening merger between two dangerous organizations.

It would indicate that Nigeria, one of Africa's top oil producers and a key supplier to the United States, could face a dangerous escalation in Islamist violence amid serious internal difficulties.

Nigerian authorities have for some time suspected that Boko Haram -- the name means "Western education is sinful" in the Hausa language of northern Nigeria -- has splintered into several factions, with Islamic extremists moving away from the parent movement.

These militants are seen as responsible for a sharp escalation in attacks in Nigeria, including suicide bombings and kidnapping Westerners that have been al-Qaida trademarks, in recent months.

Nigerian security authorities say this faction allied with al-Qaida in the Islamic Maghreb, the jihadist movement's North African branch, which has provided paramilitary training and doctrine for the Nigerian fighters whose operations until 2011 were limited to drive-by shootings and killing Christians.

Sources in Mali, where rebel Tuareg tribesmen seized the northern part of the West African state and declared it an independent state April 6, said dozens of Boko Haram fighters were seen in the rebel-held city of Gao last week.

"There are a good 100 Boko Haram fighters in Gao," one Malian official said. "There are Nigerians and men from Niger. They're not hiding."

The official said that Boko Haram members, some speaking English, "were in a majority among those who attacked the Algerian consulate" in Gao after the Tuareg secessionists captured the town March 31. Nigeria was once a British colony.

Seven Algerian diplomats, including the consul, were kidnapped. The seizure was claimed in a statement Sunday by a group calling itself the Movement for Unity and Jihad in West Africa, or the French acronym MUJAO.

Its members supposedly broke off from AQIM to focus on spreading Islamic holy war in West Africa, which includes Nigeria and Mali, rather than confine themselves to North Africa.

But MUJAO may well be a flag of convenience for AQIM, as is often the case when established organizations seek deniability for operations or to move in new directions that may seem at odds with their stated objectives.

Intriguingly, there have also been reports that Mokhtar Belmokhtar, a key AQIM leader, has also been seen in Gao since its capture by the rebels, sources in the Malian Association of Human Rights and a Niger government official said.

Belmokhtar, who operates in the southern Sahara and the semi-arid Sahel belt to the south that runs from Africa's Atlantic coast in the west across the continent to the Red Sea in the east, was recently reported in Libya buying weapons plundered from Moammar Gadhafi's arsenals during and after the eight-month civil war in Libya.

Belmokhtar operates independently from the AQIM command based in the mountains of northeastern Algeria near the Mediterranean coast.

He rules over a large swathe of desert that straddles Algeria, Chad, Niger, Mali and Mauritania and has close connections with nomadic Tuareg tribes in the region and criminal gangs smuggling South American narcotics shipped to West Africa northward to Europe.

This would make Belmokhtar, who lost an eye fighting the Soviet army in Afghanistan in the 1979-89 war and dubbed "the uncatchable" by French intelligence, the ideal contact between AQIM and Boko Haram in Nigeria to the south.

The Boko Haram-AQIM connection, espoused by Nigerian security officials and the U.S. Africa Command for several months, was bolstered by Nigeria's defense minister, Olusola Obada, Wednesday.

Obada confirmed that weapons looted in Libya at the end of the civil war, after Gadhafi's regime was toppled in a NATO-backed campaign, had turned up in Nigeria in the hands of Boko Haram.

Some of the weapons, including Soviet-supplied SA-24 surface-to-air missiles, have been reported in Egypt's Sinai Peninsula, east of Israel.

Islamists affiliated with al-Qaida have established an organization there since longtime dictator Hosni Mubarak was brought down in February 2011 by pro-democracy protests.