TUNIS (Reuters) - A group of 25 refugees have been evacuated from Libya to Niger to have resettlement claims processed, in the first operation of its kind from the North African country, the United Nations said on Sunday. The move is part of efforts to provide protection for refugees and other vulnerable migrants who travel to Libya, often intending to attempt the dangerous sea crossing to Italy.  Many are trapped in smuggling networks or detention centers where they are exposed to a range of abuses including rape and torture that have been widely documented by human rights organizations and U.N. agencies. About 43,000 refugees and asylum seekers registered by U.N. refugee agency UNHCR are now in Libya. It is hard to resettle refugees directly from Libya partly because most countries closed their embassies in Tripoli after fighting escalated there in 2014. The initial group evacuated by air from Tripoli to Niamey on Saturday was made up of 15 women, six men and four children from Eritrea, Ethiopia and Sudan, according to the United Nations.  Today s evacuation symbolizes hope in finding safe solutions for vulnerable refugees in Libya,  Roberto Mignone, the UNHCR representative for Libya, said in a statement.    The operation was the result of a joint initiative by UNHCR and the governments of Libya and Niger, and Niger has agreed to host the group until their claims to be resettled in third countries are dealt with, it said.  We hope to be able to carry out more evacuations in the near future,  said Vincent Cochetel, UNHCR s Special Envoy for the Central Mediterranean. But he said the scheme would remain  limited in scale  as long as commitments to resettle refugees remained  insufficient .  These refugee evacuations can only be part of broader asylum-building and migration management efforts to address the complex movement of migrants and refugees who embark on perilous journeys across the Sahara Desert and the Mediterranean Sea,  he said.   Most migrants traveling through Libya towards Europe come from sub-Saharan African countries. Many fleeing poverty, repression or conflict journey across the desert through Niger, Algeria or Sudan.  The Libya to Italy crossing has become the main migrant route to Europe since an agreement between the EU and Turkey shut down smuggling through Greece last year. More than 600,000 have crossed by boat to Italy since 2014.  European states have pledged tens of millions of euros to Libya, Niger and migrants  countries of origin in an effort to stem the flows. Departures from Libya have dropped since July due to changes in smuggling activity and increased activity by Libya s European-backed coastguard. European policy has drawn criticism from human rights groups that say it traps migrants in Libya, exposing them to further abuse there. UNHCR is seeking to open a refugee transit center in Tripoli early next year to shelter some of the most vulnerable refugees as they await evacuation or resettlement. The International Organization for Migration carries out voluntary repatriations of migrants from Libya, flying home more than 10,600 so far this year. 