The U.N. envoy to Libya expressed serious concern Tuesday about violence in the North African country, calling again for a cease-fire as a car exploded outside a police station in the eastern city of Benghazi. Bernardino Leon told a news conference in Tripoli, which also is controlled by militias, that the "serious concern today is the situation on the ground in Benghazi and in Jebel Nefoussa, where the cease-fire was not respected. Earlier this month, the United States urged the truce on both fronts, but fighting has continued. "The danger for the country is that in the past weeks we are getting very close to the point of no return," Leon said, adding that dialogue was the only way to end the crisis. "We want to see a cease-fire respected by all."