LONDON, UK — Scotland Yard has stepped up police security at mosques and Muslim community centers around London following a suspected arson attack on an Islamic school this weekend.

It was the second such attack on a Muslim institution in a week, and signaled that the tensions stoked by the vicious murder of a British soldier in southeast London last month have yet to cool down.

“These are difficult times for London’s communities,” Metropolitan Police commissioner Sir Bernard Hogan-Howe said. “We should not allow the murder of Lee Rigby to come between Londoners. The unified response we have seen to his death across all communities will triumph over those who seek to divide us.”

The fire forced the evacuation of 128 students and staff near midnight on Saturday from Darul Uloom Islamic School, a boys’ boarding school in southeast London. Two boys were treated for smoke inhalation, but there were no other serious injuries.

Four teenagers have been arrested in connection with the attack, police said. Police have not yet determined whether the fire was started deliberately, though it is being investigated as suspicious.

More from GlobalPost: After London attack, UK grapples with anti-Muslim rage

On June 4, a Muslim community center in a quiet north London residential community was firebombed and destroyed. The few walls of the Al-Rahma Islamic Centre left standing were painted with the letters “EDL” — a potential reference to the English Defence League, a far-right group described on their official Facebook page as “peacefully protesting against millitant [sic] Islam.”

In response to these attacks, Scotland Yard has deployed additional officers to mosques and other potential hate-crime targets, with 24/7 guards at sites considered “at greatest risk,” Hogan-Howe said.

A lone community police officer was stationed outside Finsbury Park Mosque in north London Monday. Inside, mosque chairman Mohammed Kozbar looked weary.

“Hopefully this will end soon, and then we will go back as we were before, working together and building bridges with the wider community,” he said.

In the weeks since the murder of Drummer Lee Rigby by self-professed Islamists — an attack Kozbar condemned as a “barbaric act” — the mosque had received abusive phone calls and several members, particularly women, had been harassed in the street, he said.

The police and community have been supportive, Kozbar added.

He spoke in a small and sparse office with a worn red carpet, a monitor showing 16 separate CCTV surveillance feeds, and a notice in English and Arabic prohibiting left luggage in the building.

Would a local church or synagogue feel compelled to carry the same security measures? Kozbar shook his head.

“These people are trying to divide our communities. We won’t let them do that,” Kozbar said of the attackers. “They are trying to isolate our community, the Muslim community, from the wider community.”

A link to a BBC article about the arson attempt on the school drew hundreds of comments on the EDL’s Facebook page, many in support of the attack.

“Too bad all the little muslims didnt burn,” one comment read.

“When they grow up to be suicidal bomb experts you're gonna wish they burned to death as kids! less of the sympathy,” said another.

On Monday, six Muslim men were sentenced to 19 years each for attempting to bomb an EDL rally in Yorkshire last year. The public gallery erupted at the sentencing, the BBC reported: “God save the queen!” from EDL head Tommy Robinson and his deputy, “Allahu Akbar” — God is great — from others.

The EDL has denied involvement in the destruction of the north London mosque. Police have not yet made any arrests in the ongoing investigation.

On Monday, corrugated metal barricades surrounded a small encampment of police vans and officers in front of the ruined husk of the center, which primarily served the area’s Somali community.

The center stood on a quiet road in the Muswell Hill neighborhood, next to a school and a community garden. A few yards from the police barricade was a bouquet of flowers and a sign tied to the chain-link fence.

“Sorry your centre burnt down, a place of learning and community,” the handwritten poster read. “We hope it will be rebuilt soon ... bigger and better.”

