The Prince of Wales has sent a message to the people of New Zealand in which he says the New Zealand attack is "beyond all belief".
Following the incident, The Stuff news portal reported that a Christchurch hospital was expecting to receive from 40 to 50 people injured in the shootings.
"Support to the New Zealand police who are committed against hatred and barbarism".
Forty-nine people were killed and 20 seriously injured in the shootings, which the Prime Minister has described as a "terrorist attack".
Authorities have detained three men and a woman and defused explosive devices in what appeared to be a carefully planned attack.
Two of the others remain in police custody, with a fourth person arrested deemed not to have been involved in the attacks.
French President Emmanuel Macron echoed Merkel's message, condemning an "odious attack" and saying France "stands against any form of extremism".
Pakistan's Prime Minister Imran Khan echoed Erdogan.
The secretary-general of the 57-nation Organization of Islamic Cooperation, Youssef al-Othaimeen, said in a statement that the attack "served as a further warning on the obvious dangers of hate, intolerance, and Islamophobia".
"I would never have expected anything like this to happen in Christchurch, I'd never expect this to happen in New Zealand", Dalziel said, as quoted by the Stuff news outlet.
Celebrities have since flocked to social media to pay tribute to those who lost their lives.
Metropolitan Police assistant commissioner Neil Basu said: "Today we will be stepping up reassurance patrols around mosques and increasing engagement with communities of all faith, giving advice on how people and places can protect themselves".
European Commission President Jean-Claude Juncker tweeted that he learned of the attack "with horror and profound sadness".
"My thoughts are with the family of Afghan origin who was shot and killed in this heinous incident", he wrote.
Sadiq Khan, the first Muslim mayor of London, said Londoners stood shoulder to shoulder with the people of Christchurch.
Armed police following a shooting at the Al Noor mosque in Christchurch, New Zealand, on March 15, 2019.
One of the gunmen - believed to be an Australian extremist - livestreamed the deadly assault, stoking outrage and fear that others may be targeted in copy-cat attacks.
"Far too often, Muslims suffer unimaginable loss and pain in the places where they should feel safest", Trudeau said in a statement.
New Zealand Police provided an update on the investigation, announcing that evacuations had been ordered at a residence in the city of Dunedin. "We are working to have any footage removed". "Our thoughts & prayers are with the families of the victims", Gargash wrote.
British Prime Minister Theresa May offered deepest condolences "after the horrifying terrorist attack in Christchurch".
In Europe, German Chancellor Angela Merkel said she was deeply saddened: "I mourn with the New Zealanders for their fellow citizens who were attacked and murdered out of racist hatred while peacefully praying in their mosques".
Another 48 people are being treated for gunshot wounds after what the country's prime minister, Jacinda Ardern, called "one of New Zealand's darkest days".
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