One person has been taken into custody after he opened fire inside a mosque in the Norwegian capital Oslo.
"One person is shot. The severity of that person's injuries is unknown. One suspect is arrested. The police are working at the location," Oslo police said on Twitter.
Later a woman was found dead at the house of the suspect.
"A young woman was found dead at the suspect's address," assistant chief of police Rune Skjold told the media, adding that the man was suspected of murder.
According to reports, the gunman was dressed in black and wore a helmet and bulletproof vest.

Three people die in Mexico World Cup celebrations as fans crowd streets
US and Iran enter technical talks to secure peace deal, shipping restart
After Venezuela quakes, citizens lead rescues amid military theft accusations
Two dead after wildfire guts house in northern Greece
Afghanistan launches airstrikes on IS targets on border with Pakistan
Bangladesh warns of dengue surge as weather aids spread
Fourteen children killed in Pakistan after tutoring centre roof collapses
Supreme Court rejects Trump bid to restrict birthright citizenship
