"In all boroughs across London, there is an increased police presence around locations that might be at risk,” Metropolitan Police Commissioner Sir Bernard Hogan-Howe said.
“We will maintain a 24/7 guard of uniformed officers at sites we consider to be at greatest risk.”
The move follows attacks on mosques and an Islamic school in Britain in recent days.
On Saturday, a fire gutted the Darul Uloom Islamic school in Foxbury Avenue in south-east London. Police described the blaze at the Islamic school as “suspicious”.
It came after a suspected arson attack on an Islamic centre in north London last Wednesday.
Initials of the far-right English Defence League was found scrawled on the side of that building.
The attacks came days after the machete killing of an army soldier by two converts of immigrant origin in Woolwich near London.
“The Met is now investigating suspicious fires at two locations within the Islamic community which have happened in the past few days. Fortunately no one has been hurt, but we know that fires can often prove fatal,” the police commissioner said.
“So I want to reassure people that we are using our full range of policing tactics to protect sites that might be vulnerable.
He assured the public the police are “working tirelessly to establish whether these fires were started deliberately, and if so, to catch those responsible.”
The police commissioner called for Britons to promote unity and avoid division in the wake of the soldier’s killing.
“We should not allow the murder of Lee Rigby to come between Londoners,” Hogan-Howe said.
“The unified response we have seen to his death across all communities will triumph over those who seek to divide us.”
Hostility against British Muslims has been on the rise since the machete attack, which Muslims condemned as running against the basic Islamic teachings.
Some 212 “anti-Muslim incidents” have been reported since the May 22 killing, according to Tell Mama project, which monitors anti-Muslim attacks in Britain.
The figure included 11 attacks on mosques, in a series manifestation of anti-Muslim sentiments.
Britain is home of a Muslim community of nearly 2.7 million.
Source: On Islam