Violent explosion shakes Yemen's Aden refineries: Alarabiya TV

CAIRO (Reuters) - A huge fire broke out after a violent explosion shaked Yemen’s port city of Aden's refineries, Alarabiya TV said on Friday. The reason for the explosion was unclear. U.N. Yemen envoy Martin Griffiths expressed alarm on Thursday over an escalation of violence there and urged all parties to exercise restraint. (Reporting by Mohamed El-Sherif; editing by Louise Heavens)