Political and religious leaders around the world expressed disgust and sorrow at the deadly shooting at two mosques in New Zealand on Friday, with some blaming politicians and the media for having stoked hatred of Muslims that led to the attack.

As governments in Asia and the Middle East scrambled to find out how many of their citizens had been caught up in the Christchurch bloodshed, there was anger that the attackers targeted worshippers at Friday prayers.

"I blame these increasing terror attacks on the current Islamophobia post-9/11 (where) 1.3 billion Muslims have collectively been blamed for any act of terror," Pakistani Prime Minister Imran Khan posted on social media.

Turkish Foreign Minister Mevlut Cavusoglu said the attack was a result of the demonising of Muslims. "Not only the perpetrators, but also politicians & media that fuel the already escalated Islamophobia and hate in the West are equally responsible for this heinous attack," he wrote on Twitter.

Bangladeshi Minister of State for Foreign Affairs Shahriar Alam said it was "extremely lucky" the country's cricket team, in Christchurch for a match against New Zealand, did not suffer casualties. The players arrived for Friday prayers as the shooting started.

"I can't even imagine what would have happened if they were there five minutes earlier," he said on social media.

Hundreds of angry protesters in Dhaka, Bangladesh's capital, chanted "allahu akbar" (God is Greatest) after Friday prayers.

"We will not let the blood of Muslims go in vain," said one protester.

SEARCH FOR VICTIMS

New Zealand police said 49 people were killed. Three men and one woman were in custody and one man had been charged with murder. Prime Minister Jacinda Ardern said some of the victims may have been new immigrants and refugees.

"They are us," she said. "The person who has perpetuated this violence against us is not. They have no place in New Zealand."

Australian Prime Minister Scott Morrison said an Australian national arrested after the attack was an "extremist, right-wing violent terrorist".

A city of about 400,000 people, Christchurch has a small Islamic community, including overseas students.

Britain's Queen Elizabeth, the head of state of New Zealand, said in a statement: "I have been deeply saddened by the appalling events in Christchurch today. Prince Philip and I send our condolences to the families and friends of those who have lost their lives."

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. We stand together against such acts of terrorism."

The European Commission said: "This senseless act of brutality on innocent people in their place of worship could not be more opposite to the values and the culture of peace and unity that the European Union shares with New Zealand."

Sadiq Khan, the first Muslim mayor of London, said Londoners stood shoulder to shoulder with the people of Christchurch.

"When the flames of hatred are fanned, when people are demonised because of their faith, when people's fears are played on rather than addressed, the consequences are deadly as we have seen so sadly today," he said.

Norwegian Prime Mininster Erna Solberg said the attack brought back memories of 2011 in her country when anti-Muslim extremist Anders Breivik killed 77 people: "It shows that extremism is nurtured and that it lives in many places."

Al-Azhar University, Egypt's 1,000-year-old seat of Sunni Islamic learning, called the attack "a dangerous indicator of the dire consequences of escalating hate speech, xenophobia, and the spread of Islamophobia."

Ordinary people expressed horror over a live, point-of-view video posted online showing a gunman involved in the attack killing any person he came across in a mosque with his semi-automatic assault rifle.

"Feeling very sick, that person is brainless and a savage," said one Indonesian Twitter user who identified himself as Farhan Adhitama.