A branch of Germany's AfD party apologized on Wednesday for publishing and distributing a coloring book that contained "racist" images of Turks, Muslims and black people.

AfD's regional branch of North Rhine-Westphalia handed out the coloring book at a public event on Monday prompting outcries after pages of the book were shared on social media.

One page of the book showed a swimming pool filled with people with bones in their hair and thick lips harassing female bathers. Many recognized this as racist imagery used to depict black people as savages. Muslim women in full-body veils were also drawn on the page.

On another page, a caricature showed men armed with guns, some wearing the traditional Turkish Fez headdress, and women in headscarves waving Turkish flags.

AfD's parliamentary group initially defended the coloring book as "satire" but later issued an apology saying the book was "published prematurely" and "went beyond the goal of satirically exaggerating problematic processes."

In its statement, the group also said that distributing the book in its current form was "an organizational mistake", adding that the project had been canceled.

"Although the majority of the sketches remain within the scope of the project, there are some that are definitely not okay and of course do not reflect the opinions of the parliamentary group," the group said.

The incident provoked a  severe backlash as it took place on the backdrop of a terrorist in Germany on Thursday, in which a gunman with apparent far-right beliefs shot dead nine people of migrant backgrounds at a shisha bar in Hanau. Five of those killed were said to be Turkish nationals.

Twitter user Wonder Woman said in a tweet: "In a time in #Germany where #AfD is allowed to distribute coloring books with #racist content to children, I am in shock but not entirely surprised about the #HanauShooting."

A German politician from the center-left Social Democratic Party (SPD), Thomas Kutschaty, also tweeted saying the AfD had "published a racist coloring book" that belonged in the bin.

The AfD, which has shaken up Germany's political landscape since it was founded in 2013, is now the biggest opposition party in the national parliament. The party is considered far-right for its anti-immigrant and anti-Islam positions.

Police in Germany's western city of Krefeld have said they were investigating a complaint of incitement to hatred filed against the AfD's North Rhine-Westphalian parliamentary group.

A speaker for the North Rhine-Westphalian parliament also said they were carrying out investigations to determine whether the book was paid for with public funds.