In both cases, the perpetrators are thought to have deliberately targeted people affiliated with the Syndikalist trade union.

On Saturday evening, the Cyklopen social centre in the Högdalen suburb burned to the ground in what police believe was a deliberate attack. The fire broke out at the same time an anti-racist group was scheduled to meet at the centre, though the meeting had been cancelled a few days earlier.

Two nights later, a couple and their young child were forced to evacuate their Högdalen apartment after flammable liquid was poured through their letterbox and the premises set on fire, Dagens Nyheter reports.

The father, 27, and mother, 24, fled to the balcony as the apartment became engulfed in flames. They managed to pass their 2-year-old daughter down to their neighbour one floor below before hoisting themselves over over the balcony to safety.

“We are working on the theory that Nazis were behind this,” police investigator Christer Söderheim told the newspaper.

With both parents active in the Syndikalist movement, Söderheim said he believed the two recent attacks were linked.

The events of the last few days come nine years after Syndikalist Björn Söderberg was murdered by two Nazis outside his front door in the Stockholm suburb Sätra.

Swedish security police Säpo said it was not unusual for clashes to intensify in the period leading up to December 6th, when Swedish neo-Nazis stage an annual march in the small town of Salem to mark the violent death in 2001 of 17-year-old white power advocate Daniel Wretström.

“It’s more intense this year than ever before,” Säpo spokesman Johan Olsson told Svenska Dagbladet.