New Zealand police are responding to the incidents and local TV are reporting multiple casualties.
The locations involved are said to be Al Noor Mosque on Deans Avenue near Hadley Park in the centre of the city and Masjid Mosque in the suburb of Linwood.
The incidents unfolded during Friday prayers, the busiest time of the week for worshippers.
Stuff.co.nz report the shooters' rifles had the names Alexandre Bissonette and Luca Traini scrawled on them - both past mosque shooters from Italy and Canada.
7 News say dozens of shots were fired and there is a heavy police presence at Christchurch Hospital.
Another mosque goer was seen outside crying and saying "they shot kids".
Stuff.co.nz claim a man said there were "bodies all over me".
Police have ordered schools to go into lockdown and urged anyone in central Christchurch to stay indoors.
Members of the Bangladeshi cricket team were praying in the mosque when shooting broke out.
All are reported to have escaped to safety across Hagley Oval, per Yahoo Sport.
The shooter was described as blonde, Caucasian and of short build.
He was said to be wearing a helmet and a bullet proof flack vest.