Pictures of the graffiti were taken immediately and police were called.
"Right now, in these days, what we want to do is make sure we are protecting the congregation," said Ali Jomaa, chair of the board for the mosque. "Knowing what happened in New Zealand we wanted to make sure that we are taking all the precautions necessary."
Fifty-one people were killed when a gunman opened fire at two mosques in New Zealand. A 28 year old white supremacist was arrested and charged in the case.
"We wanted to make sure we are taking all the precautions necessary in regards to any hate or any type of messaging," said Jomaa.
The mosque also ensures it has the latest technology to protect members of the congregation, said Jomaa.
"We have sought advice from our security consultants and local police," he said. "Our security system is probably one of the most up to date security systems in the city of London."
Jomaa said the mosque has a good working relationship with London police who have been quick to respond to incidents and offer help in anyway. This incident was no exception.
The community outreach is also quite active he said.
"A lot of non-Muslims come to the mosque. A lot of people who are friends come on a regular basis to meet and greet with us. School groups also tour the mosque to learn more about Islam."
Officials from the London Muslim community issued this written statement in response to the vandalism.
"We need to keep doing our job as a Muslim mosque and Muslims as a whole to stay positive, proactive, engaging and at the service of the London Community, Muslim and otherwise. Although these acts of intolerance are unfortunate we can't let them bring us down. Maybe those who commit them will see the light when they realize that we are an asset and vital segment of London and that we are friends and not enemies," it read.
Despite the hateful graffiti, Jomaa said he's not worried and he doesn't believe most members are either.
"I'm sure that people understand that there's a minority of people who spread hate. The majority of people around London are very supportive," he said. "We have no worries about that. We're taking extra precautions to make sure that nothing happens."