LAGOS, Nigeria (AP) — The buses crammed full of young men leave each afternoon from this busy market in Nigeria's largest city, some with bruises around their faces and cuts on their arms.

A series of raids by Nigerian authorities in recent days has brought fear to Katangua Market in Lagos, where immigrant labor makes the market thrum amid piles of secondhand clothes, shoes, purses and other accessories that are laid along narrow dirt alleyways. Immigrant workers, who come largely from neighboring Niger to the north, are finding themselves targeted by security agencies anxious about a growing Islamic extremist insurgency in northern Nigeria that could spread southward.

Nigeria's porous borders and corrupt bureaucracy allow people to enter the country, giving extremists the chance to freely move and avoid capture. But those same borders give those living in poverty in neighboring countries a chance to earn money. Now even immigrants with proper travel documents worry they'll be rounded up as well.

"If they come here and arrest me and I don't have my papers, I don't know what's going to happen," said Abdu Tanimu, a leader of Nigeriens working in the market. "I don't know what's going on out there."

Immigration raids have happened before and even have a place in the slang of oil-rich Nigeria, home to more than 160 million people. The colorful recycled plastic bags carried by travelers in the region are known as "Ghana-Must-Go," a reference to when Nigeria kicked out Ghanaians and other immigrants in 1983 as oil prices collapsed and the country's economy cratered.

Today, immigrants make up much of the menial labor workforce in Lagos. Nigeriens push wheelbarrows and carry goods on their heads in markets, while others serve as gate guards and night watchmen in commercial properties and residential estates. Young men from Benin, Cameroon, Chad, Ghana and other nations also crowd into the city, looking for jobs.

While some carry a proper passport and work permit, the majority of immigrants simply cross the border without papers. Some pass through with a payment of less than $1 to immigration officials. Others simply drive through the unpatrolled sandy stretches of the Sahel into Nigeria.

That loose arrangement is now being challenged, however, by a growing wave of shootings, bombings and kidnappings carried out by Islamic extremists in Nigeria's predominantly Muslim north. Since 2010, the extremists' guerrilla campaign has killed at least 1,548 people, according to an Associated Press count. Authorities and civilians increasingly fear that violence could spread into Lagos and Nigeria's largely Christian south, potentially destabilizing the nation.

"Now that there's insecurity in the country, those of them who came in here without the regular traveler certificate are the ones being sent out of the country," said R.O. Odupeyin, the Lagos state comptroller of the Nigeria Immigration Service. In recent weeks, the service has deported some 345 Nigeriens and 11 Ghanaians, Odupeyin told the AP. Another 22 Malians have been arrested and handed over the United Nations refugee agency as French and Malian forces continue to fight Islamic extremists there, Odupeyin said.

However, critics point to the fact that nearly all those arrested in connection with extremist groups come from Nigeria and are not foreigners. That means while those arrested may have violated immigration laws, the arrests have little value in Nigeria's current fight against the radical Islamic extremist network Boko Haram and others.

"The Nigerian government knows the Boko Haram," said activist Declan Ihekaire, a Nigerian. President Goodluck Jonathan "once told Nigerians openly that he has members of Boko Haram within his Cabinet and if that is correct, the government should look for Boko Haram where they know they are — not going to all these market places (arresting) poor people."

Soldiers, police officers and Nigeria's domestic spy agency repeatedly have raided Katangua Market, a sprawling maze of shops where tons of clothes from the Western world — some likely donated — are resold. In the latest raid on April 9, authorities arrested 251 suspected illegal immigrants, Lagos state police spokeswoman Ngozi Braide said. While some have been released, others remain held at state government headquarters in Lagos, likely to be handed over to the immigration service for deportation.

Signs of the raid on the market remained days later.

Yushau Ibrahim stood near the metal door that security forces broke down, his still-bleeding hand wrapped in a sling made out of a man's black tie. Ibrahim said police officers beat him and stole nearly $10,000 he held for local moneychangers. Other merchants said officers stole money from them as well, something Braide denied. He said that during the raid, young boys sleeping in the local mosque jumped down and ran when authorities began firing sporadic gunshots.

The police arrested immigrants who couldn't immediately show their stamped passports. That worries Tanimu, who has children who were born and only have lived in Nigeria. Once, authorities arrested his 15-year-old son and for a while refused to release him.

"He was born here. He doesn't know anywhere else," Tanimu said in the Hausa language of northern Nigeria and neighboring countries. "They wanted to take them back to Niger. My worry was where are they taking him to? Is he going to look for his parents in a place he doesn't know?"


Associated Press writers Sunday Alamba and Lekan Oyekanmi contributed to this report.


Jon Gambrell can be reached at .