U.N. pushing sharp increase in migrant returns from Libya

By Aidan LewisTUNIS (Reuters) - The United Nations migration agency is stepping up the rate at which it flies migrants home from Libya, aiming to evacuate up to 15,000 in the final month of the year.The acceleration of returns is an attempt to ease severe overcrowding in detention centers, where numbers swelled after boat departures for Italy from the smuggling hub of Sabratha were largely blocked this year.It also followed a CNN report showing migrants being sold for slave labor in Libya, spark