against criminal groups, as clashes and explosions were heard. Security forces and military units carried out raids and arrests from dawn across the city west of the capital, Tripoli, by just some 45 kilometres (28 miles), an official statement said. The operation went after "criminal hideouts and wanted individuals" who were "involved in serious acts", the authorities said, citing "murder and attempted murder, kidnapping and extortion, drug, arms and human trafficking, and illegal migration". While authorities have yet to confirm any casualties, the UN Support Mission in Libya later in a statement condemned the clashes "amid disturbing reports of civilian casualties". "The use of heavy weapons and indiscriminate fire in densely populated neighbourhoods is unacceptable," the mission said. "Civilian infrastructure must not be turned into battlefields," the mission added. "All parties must immediately halt such practices and immediately cease hostilities as a matter of urgency." Videos circulating on social media, which AFP could not independently verify, appeared to show armed clashes in residential neighbourhoods and near the refinery complex -- one of Libya's most important -- on the western outskirts of the city. A Zawiya resident reached by AFP by phone said "the first clashes began in the early hours of Friday", adding that they heard "explosions across the city". Local emergency services urged residents to remain indoors while midday Friday prayers -- when large numbers of worshippers go to mosques -- were set to take place. The city of some 250,000 people has experienced repeated fights between armed groups. (Bssnews)