JINAN, March 30 (Xinhua) -- Five people were killed in an explosion in a factory in east China's Shandong Province Friday evening, according to local authorities.

The explosion happened at 9:35 p.m. in a workshop of a perlite factory in the city of Qingzhou. Another three people were slightly injured outside the workshop.

The private factory owner was held by the local police. Initial investigation showed the accident was caused by a leak in a liquified gas tank. Further investigation is underway.