China's media watchdog will investigate an anti-Japan television serial that viewers have criticized as vulgar for a scene showing a woman making use of a grenade concealed in her crotch to kill Japanese soldiers, state media said on Thursday.

Ties between the neighbors have been shadowed for years by what Beijing calls Japan's refusal to admit to wartime atrocities by its soldiers in China between 1937 and 1945.

These accounts are taught to every Chinese schoolchild and form a staple of television dramas.