BERLIN - German Chancellor Angela Merkel led condemnations on Tuesday of a "politically motivated" gang attack against a far-right German MP, an assault that underlined an increasingly tense political atmosphere.

Frank Magnitz, leader in Bremen of the anti-immigration populist party Alternative for Germany, or AfD, was badly injured in the assault in the city center on Monday afternoon.

"Given the victim's work, we believe that this is a politically motivated act," police said.

The AfD party published a photo of Magnitz unconscious on a hospital bed, his face bleeding and swollen with a gash on his forehead.

It said three masked men had carried out the attack.

"They hit him with a piece of wood until he was unconscious and then kicked him on the ground," a statement from the party said, adding that a construction worker had intervened to stop the assault.

"Today is a dark day for democracy in Germany."

Magnitz, who is still in the hospital, told national news agency DPA that he neither saw the attackers nor heard them say anything.

AfD leader Joerg Meuthen tweeted that Magnitz was "beaten almost to death" in a "cowardly and sickening" attack.

Merkel's spokesman Steffen Seibert wrote on Twitter that the "brutal attack" was "to be condemned sharply".

"Hopefully the police will succeed in catching the perpetrators quickly," he wrote.

Foreign Minister Heiko Maas said there was "absolutely no justification" for the use of violence despite political differences.

Interior Minister Horst Seehofer said: "There's zero tolerance for violence, whoever is affected and wherever the violence comes from. We need to do everything to find the culprits and hold them to account."

Multiple attacks

The AfD's entry into parliament in September 2017 with 13 percent of the vote unleashed a political earthquake in Germany.

With their anti-immigration rhetoric and their challenge of post-World War II Germany's culture of atonement, the party's leaders and MPs have been overturning one taboo after another in the country's political arena.

While they have won fans in some quarters and are projected to make gains in European elections in May as well as three regional polls in Germany's east region this year, they have also sparked furor and become a target of attack.

Last week, an explosive device detonated in a rubbish bin damaged an AfD office in Saxony. Three suspects were detained.

And last weekend in Lower Saxony, the home of a local AfD politician was targeted with graffiti and a party office was attacked with a paint bomb.

Since mid-December, German police have recorded eight attacks against AfD offices.

Party co-chiefs Alexander Gauland and Alice Weidel called the latest assault the "result of the incitement to hatred by politicians and media against us".

German President Frank-Walter Steinmeier wrote to Magnitz to express his "consternation" over the attack.

"Our democracy needs controversies, exchanges with arguments, even when this gets heated. But we must never allow political violence-regardless from which side," he wrote, according to DPA.

AFP-AP