BRUSSELS - A gunman killed four people, including himself, in an attack in the Belgian city of Liege on Tuesday, Belgian media reported.The man, named by Belgian press agency Belga as 32-year-old Nordine Amrani, opened fire and threw explosives on a city center square which was hosting a Christmas market.A judicial source told Reuters that at least three people, including the gunman, had died, and some fifteen were wounded.Police and justice officials either declined to comment or were not immediately available.Local bus operator TEC said that its buses were no longer able to enter the city center. A museum located on the square said it had taken in injured people."As we are very close and we have an open space where you can enter and leave with no problem. I can say there were injured, but don't ask me if it's five, seven, eight or nine. I don't know," said Archeoforum director Jean-Jacques Messiaen.