DETROIT (AP) -- Media reports say an underground explosion has caused damage in downtown Detroit.
WXYZ-TV reported that authorities said Saturday morning's explosion happened at an underground electrical substation in the central business district.
WWJ-AM, WXYZ and WDIV reported the blasts blew manhole covers into the air.
There were no immediate reports of injuries.
A Detroit Police spokeswoman said more information would be released later. The Associated Press left a message with fire representatives.