Hundreds of people have gathered to pray for the victims of the Christchurch shootings at Sydney's Lakemba Mosque.

Key points: Australia's peak body of Islamic councils described the shooting as an "act of terror"

Australia's peak body of Islamic councils described the shooting as an "act of terror" Leader Rateb Jneid said politicians must be aware of the consequences of an atmosphere of "hate and division"

Leader Rateb Jneid said politicians must be aware of the consequences of an atmosphere of "hate and division" Mosques and Muslim worshippers across Australia are urged to be "extra vigilant"

Police said 49 people were killed in mass shootings targeting worshippers at two mosques in Christchurch, in what New Zealand's Prime Minister Jacinda Ardern labelled "one of New Zealand's darkest days".

There was a strong police presence at the vigil, ahead of which Lebanese Muslim Association president Samier Dandan said there were concerns mosques in Australia could be targeted.

"It is definitely a fear, we have actually taken some action — we've called our local police commanders, we've spoken to many different police in regards to increasing the security measures across all places of worship," he said.

Mr Dandan condemned the terrorist attack and said his thoughts were with the victims.

"Such a deplorable act of terror has found its way to the shores of our closest neighbour, bringing out the destructive political views of white nationalism," he said.

Other Islamic leaders have also condemned the shooting attack as an "act of terror" inspired by Islamophobia.

The Australian Federation of Islamic Councils (AFIC) urged governments in Australia at all levels to pay extra attention to anti-Muslim sentiment and extremism.

AFIC president Rateb Jneid said in a statement that the victims and their families were in his prayers.

"It is with deep sorrow that we learn today of the terrorist attack committed against innocent worshippers at a Mosque in Christchurch, New Zealand," Dr Jneid said.

"We extend our prayers and thoughts to the victims and survivors, their families and the people of New Zealand during this terrible time," he said.

"This act of terror on innocent worshippers is an atrocity and we grieve with the victims and their families."

Politicians warned against 'atmosphere of hate and division'

Australia's first female Muslim senator, Mehreen Faruqi, condemned anti-Islam sentiment in Australia, particularly "far-right [politicians] like Pauline Hanson and Fraser Anning".

"There is blood on the hands of politicians who incite hate. To me, there is a clear link between their politics of hate and this sickening, senseless violence in Christchurch," she tweeted.

"Muslims have been targeted during Friday prayers. This is not an isolated event with mysterious causes. This is not random. This is the consequence of the Islamophobic and racist hate that has been normalised and legitimised by some politicians and media."

"Attending Friday prayers is a family ritual for millions of Muslims. My heart breaks for everyone who has lost family and friends today, and Muslims around the world who worry for their safety each day.

"Let's call this what it is. A planned terrorist attack targeting Muslims."

The president of AFIC said the shooting was "a product of the ever-increasing Islamophobia and marginalisation of Muslims". ( AP: Mark Baker )

Dr Jneid said in the statement that Muslims in Australia needed to be aware of their safety, especially around mosques.

"We encourage all Mosques and places of worship in Australia to be extra vigilant and for members of the Muslim community to be particularly mindful of their safety in the coming days," he said.

He also urged Australian governments to be aware of the "horrific consequences" that can flow from hate speech.

"This massacre today is a product of the ever-increasing Islamophobia and marginalisation of Muslims and is a reminder to all concerned, including political leaders and media commentators, of the horrific consequences that an atmosphere of hate and division can lead to," he said.

"No country or community is immune to such atrocities.

"We urge governments in Australia, both at a Federal and State level, to give extra attention to the rise of anti-Muslim sentiment and extremism and ensure that the concerns of the Muslim community are being genuinely heard and responded to."