Sun Express, Smoke in Cabin

A Sun Express Deutschland Boeing 737-800, registration D-ASXQ performing flight XQ-4879 from Stuttgart (Germany) to Hurghada (Egypt), was enroute at FL350 about 130nm westsouthwest of Belgrade (Serbia) when the crew decided to divert to Belgrade reporting smoke in the cabin. The aircraft landed safely on Belgrade's runway 12 about 25 minutes later. The airport reported the aircraft diverted due to a smoke indication in the cabin. The aircraft remained on the ground for 20 hours over night, then continued the flight and reached Hurghada with a total delay of 21 hours.

Source: http://www.avherald.com/h?article=4ac3a8fb&opt=0