 Hundreds of migrants and refugees waited outside a United Nations centre in Tripoli today to seek help in escaping Libya. They are trying to escape what aid groups call a violent crackdown in which thousands have been arrested and several shot. The migrants say they have faced violent abuse and extortion in a country that has had little peace for a decade. The mentioned practice is like beating, imprisonment and subjection to torture. Armed forces in Tripoli began a series of mass arrests a week ago, detaining more than 5,000 people in overcrowded detention centres. The North African country has become a major transit point for people seeking to reach Europe in search of a better life.