At least 66 people have been killed in a series of car bombs targeting mainly Shia areas in the Iraqi capital, Baghdad, police say. Many more were wounded as at least a dozen explosions hit busy shopping areas and markets in the city. There has been a recent marked rise in attacks in Iraq linked to growing political and sectarian tension. It has raised fears of a return to the levels of sectarian violence seen in 2006 and 2007, in which thousands died.