After a terror attack at two mosques in Christchurch, New Zealand that killed 49 people and left dozens injured, the world is reacting with concern and condemnation.

London Mayor Ed Holder released a statement Friday saying he is both shocked and saddened by the news of what happened Friday morning.

"On behalf of all Londoners, my thoughts and prayers are with the people in Christchurch who are now mourning the loss of their friends and family members. With a heavy heart, I add my voice to the many voices from around the world condemning this horrific act of terror. People everywhere should be able to gather for worship, free of fear."

The Canadian flag at city hall was lowered to half-mast to "mourn the senseless losses and pay our respects," the mayor said.

And student groups at Western University are organizing a 'London Solidarity Vigil for New Zealand Mosque Attacks' at 6p.m. Monday at Victoria Park.

The gathering is described as a chance to, "remember the victims, their families, and communities of the New Zealand Mosque terror attacks, and let us come together as a community against Islamophobia, xenophobia, anti-Semitism, white supremacy and other and all forms of racism, hatred and bigotry. "

The London Muslim Mosque meanwhile released a statement on Facebook that said, in part, "Our most heartfelt prayers go out to the deceased and their families. We share their pain and sorrow, and we mourn them like our own."

They say they had been in contact with London police for additional presence and were increasing security personnel for Friday prayers.

Mosque security heightened

There has also been a boost in police presence at a number of Ontario mosques.

In Toronto, Hamilton, Peel Region and York Region, police all say they're ramping up the number of officers around places of worship, with particular attention to mosques.

However, the police forces say they have not received reports of threats or suspicious activity.

The shooting in New Zealand came during busy Friday prayers at the Christchurch mosques.

Muslim community leaders say it's hard to feel safe in the wake of such an open act of Islamophobia.

With files from The Canadian Press