Police in Greater Manchester have arrested a man after becoming aware of a social media post in support of the New Zealand terrorist attacks.
Fifty people are now known to have been killed in the shootings at a mosque in Christchurch.
Police say the 24 year old man from the Oldham area is now under arrest on suspicion of sending malicious communications.
A GMP spokesman said: “This is a very difficult time for people. The events in New Zealand have reverberated around the world. Many people are in deep shock and are worried.
“It is at times like this that, as a community, we stand together.
“Where the law permits and people cross the line, we will take robust action, which may include arrest and prosecution.”
British security sources said there were no apparent UK links to the attack.
Thirty-four people remain in hospital with injuries. 12 of them are in intensive care.