The United Nations began bringing African refugees to Italy from Libya on Friday, evacuating them from detention centers whose conditions have been condemned by humanitarian groups as inhumane.

Hundreds of thousands of migrants have fled conflict or poverty at home and are now trapped in Libya, where they had hoped to pay people smugglers for passage to Europe via Italy.

It is the first time the U.N. High Commissioner for Refugees (UNHCR) in Libya has evacuated refugees directly to Europe. An Italian C-130 military plane landed at an airport south the capital carrying 110 women and children, and a second flight is expected to bring more than 50 people later in the day.

The African migrants, including many small children, were covered in blankets or bundled in coats as they disembarked from the plane on a chilly evening.

"We really hope other countries will follow the same path," Vincent Cochetel, UNHCR's Special Envoy for the Central Mediterranean, said in a statement after the first plane arrived.

"Some of those evacuated suffered tremendously and were held captive in inhumane conditions while in Libya. Five of these women gave birth while in detention, with only the very limited medical assistance," Cochetel said.

The UNHCR estimates about 18,000 people are being held in detention centers for immigrants that are controlled by the Tripoli government and it aims to evacuate as many as 10,000 next year.

"Some of those evacuated suffered tremendously and were held captive in inhumane conditions while in Libya. Five of these women gave birth while in detention, with only the very limited medical assistance," Cochetel said.

The UNHCR estimates about 18,000 people are being held in detention centers for immigrants that are controlled by the Tripoli government and it aims to evacuate as many as 10,000 next year.

Italy's move to open a safe corridor for some of the migrants follows criticism by rights groups who have condemned the country's efforts to block migrants in Libya in exchange for aid, training and equipment to fight smuggling.

"This should be a point of pride for Italians," Interior Minister Marco Minniti told reporters on the tarmac. "This is the just beginning. We will continue to try to open this humanitarian corridor."

Migrant smuggling has flourished since the overthrow of Muammar Gaddafi in 2011, with more than 600,000 making the perilous journey across the central Mediterranean in four years.

Tens of thousands of migrants are estimated to be detained by smugglers, and the African Union says that as many as 700,000 migrants are in Libya. The UNHCR has registered more than 44,000 as refugees and asylum seekers.

The UNHCR classifies Friday's arrivals as "vulnerable" refugees, which means they are children, victims of abuse, women, the elderly or have disabilities.