Armed men attacked police headquarters in the Libyan city of Benghazi on Thursday, killing three people and wounding at least 10, security and medical officials said.
"An armed group attacked the police headquarters in Benghazi trying to free suspects who were arrested a few days ago," a security official told AFP.
"The army intervened to defend the building. Five policemen were wounded and a resident of the neighbourhood (was) killed," he added.
A medical official at Al-Hawari hospital, where some of the casualties were taken, gave the same toll. An official at the Benghazi Medical Centre said without elaborating that it had received two dead and five wounded.
Security sources said the incident began as a peaceful demonstration, with protesters demanding the release of a suspect allegedly involved in the killings of several police and military officers.
Signup to our newsletter and follow us on Facebook and Twitter!
Then some demonstrators, most of them Islamists, began firing at the building, the same sources added.
Interior Minister Ashour Shuwail called for restraint in a statement carried by the official news agency LANA, adding that the arrested suspects had been transferred to Tripoli for security reasons.
Shuwail urged all parties in Benghazi to allow the "judicial authorities to investigate the incidents that have taken place in the city."
There has been a series of attacks targeting police stations in Libya's second city, with many blaming the violence on Islamist extremists.
Benghazi was the cradle of the 2011 uprising that toppled Moamer Kadhafi. It has increasingly become a focus for jihadist groups, including militants who killed US Ambassador Chris Stevens and three other Americans on September 11.