There are first reports of a blast on a bus in Jerusalem. It sounds like a big one. They're already talking about fatalities.
Update 21:35: First pictures. The bus, coming from the Western Wall, was full of kids. It was one of those big double buses and it was full.
Update 22:20: At least 18 murdered, over 100 injured, 13 of them critically. Many of the murdered were small children it seems.