Extreme-left activists have claimed responsibility for an arson attack on two police vehicles overnight in Hamburg. 

Unidentified perpetrators set fire to a police Mercedes Sprinter that was parked outside Mayor Olaf Scholz's residence for his protection. Ten minutes later a Mercedes Viano that belonged to the police union and was in sight of a police station was also torched.

Police said they suspected the attack could be related to the July G20 summit. The port city has been cited as a hub for extreme-left activism.

"We can not rule out that this act was politically motivated," said police spokesman Oliver Malchow on Friday.

Fire and flame for the police

An extreme-left group claimed responsibility for the attack in a Friday post on an online anti-corporate platform.

The group called itself "Fire and Flame for the Police" (FFdP) and said it was taking action in face of what it regarded as threats of violence from the police in light of possible riots at the G20 summit in July. Germany currently holds the G20 presidency.

"It is quite clear that in the event of a loss of control during the G20 summit, the possibility of dead demonstrators can not be ruled out," the group claimed in the post.

Police now had one less vehicle to provide the coffee during the summit, and one less vehicle to block their planned protests, the group said. "This may not be much, but it can be repeated at any time by all those who decide to do so."

London and Genoa activists 

The group referred in its statement to Ian Tomlinson, a newspaper vendor who died after being struck by a police officer during the 2009 London G20 protests. The officer who struck him was found not guilty of manslaughter but was fired for gross misconduct.

It also recalled Carlo Giuliani, an Italian anti-globalization activist who was shot dead by a police officer during protests at the G8 summit in Genoa in 2001. Giuliani was allegedly one of those who attacked a stalled police car.

'Left terror'

The ruling Christian Democratic Union (CDU) party condemned the attacks. "Violence against the police is violence against all of us," spokesman Dennis Gladiator, told national broadsheet "Die Welt."

"All people of Hamburg and all the peaceful guests must be safe during the summit," the CDU said.

Spokesman for the far-right Alternativ for Deutschland (AfD) party, Dirk Nockemann, told the paper: "It is a cowardly and repulsive attack on our police but also on our democracy."

Public broadcaster NDR reported similar attacks occurred ahead of the OSCE meeting in Hamburg in December.

aw/jm (AFP, dpa)