Police in Nigeria have freed more than 100 children from human-smuggling rings in recent days. The rescues highlight government efforts to fight the practice but show Nigeria still has a long way to go in its war on child-trafficking.

It was a refrigerated truck, normally used for shipping frozen fish, that a police surveillance team stopped in Lagos Sunday. Officers said it was the demeanor of the driver and his two passengers that first tipped them off.

When they opened the cargo compartment, they discovered 64 children packed inside. Most were young girls, some as young as one year old. None was older than 14.

Just two days before, police on Nigeria's border with Benin arrested four people caught smuggling 52 children into the country. And last week, officers raided an orphanage in Lagos on suspicions it was being used as a front for child-trafficking.

The head of UNICEF Nigeria's child protection program, Dr. Robert Limlim, says, though such practices are not new, they are being aggravated by both domestic and external factors.

"The situation of child trafficking is an old phenomenon, which is being fueled by the questions of poverty, including the questions of unemployment and child labor that is rampant in some of the places in Nigeria," he said. "And of course, it's being fueled also by the trade around prostitution."

In 2003, a survey published by the government reported that in Nigeria around fifteen million children were involved in child labor. It said 40 percent were at risk of being trafficked either domestically or abroad.

That same year Nigeria responded to the growing problem by passing a law banning human trafficking and creating a special law-enforcement agency to combat it. But the newly formed National Agency for the Prohibition of Trafficking in Persons soon found the criminal activity was both deeply entrenched and highly complex, says agency spokesman Orakwe Arinze.

"Trafficking is very serious," he said. "Nigeria unfortunately has been said to be a route, a destination, a transit country. Actually, it's unfortunate to say that Nigeria is the only country in the whole of Africa that has such a terrible remark being said about it."

Mr. Arinze says he is encouraged by the progress being made. But his agency, he says, is young and still has a very long way to go if it is to eradicate the practice entirely. For that, he is counting on the help of the international community.

"If it's something, a crime, that originates in Nigeria, it becomes solely a Nigerian problem," he said. "But it's not solely a Nigerian problem. So we're asking destination countries to help us, because they are the terminal points of these cases of trafficking. Because the industries where our children, our youths, are being supplied are not here. They are supplied to these industries, child sex industries, pornographic industries, that exist in Europe."

A total of seventeen people were arrested in Nigeria in the last week alone, on suspicion of child trafficking.