TRIPOLI (Reuters) - Fierce fighting erupted in the Libyan capital, Tripoli, during the night and continued into Saturday morning, with rival factions trading intense gunfire and several loud explosions resounding across the city. Witnesses said the clashes erupted in downtown Tripoli amid a political crisis over control of the Libyan government that has seen a growing mobilization of armed groups around the capital in the past few weeks. Pictures and videos circulating online of the city center, which Reuters could not verify so far, showed military vehicles speeding through the streets, fighters shooting, and local residents trying to put out the fires. "This is horrific," said Abdel Moneim Salem, a resident of central Tripoli. "My family and I could not sleep because of the clashes. The sound was very loud and very frightening." "We stayed up in case we had to leave quickly. It's a terrible feeling," he added. The Ministries of Interior and Health have not issued any comment so far about the fighting, which stopped late in the morning, or about casualties. The main confrontation in Libya between the national unity government in Tripoli led by Abdel Hamid al-Dabaiba and a rival administration led by Fathi Bashagha is backed by the parliament in the east of the country. The United Nations mission in the country this week warned against any attempt to resolve the conflict with violence.