A gunman opened fire on Friday prayers at a mosque in New Zealand killing many worshippers and forcing the city of Christchurch into lockdown, in what looked set to be the country’s worst ever mass shooting.

New Zealand media reported that between nine and 40 people were killed, but the death toll could not be confirmed. Police said multiple fatalities had occurred at two mosques, but it was unclear how many attackers were involved.

Video footage widely circulated on social media, apparently taken by a gunman and posted online live as the attack unfolded, showed him driving to one mosque, entering it and shooting randomly at people inside.