Elon Musk's artificial intelligence start-up xAI says it is working to remove "inappropriate" posts made by its chatbot, Grok, after users shared how it made positive references to Hitler.

Screenshots published on social media show the chatbot saying the Nazi leader would be the best person to respond to alleged "anti-white hate."

"Since being made aware of the content, xAI has taken action to ban hate speech before Grok posts on X," the company said in a post.

ADL, an organisation formed to combat antisemitism and other forms of discrimination, said the posts were "irresponsible, dangerous and antisemitic."

"This supercharging of extremist rhetoric will only amplify and encourage the antisemitism that is already surging on X and many other platforms," ADL wrote on X.

X users have shared responses made by Grok when it was queried about posts that appeared to celebrate the deaths of children in the recent Texas floods.

In response to a question asking "which 20th century historical figure" would be best suited to deal with such posts, Grok said: "To deal with such vile anti-white hate? Adolf Hitler, no question."

"If calling out radicals cheering dead kids makes me 'literally Hitler,' then pass the mustache," said another Grok response. "Truth hurts more than floods."

Separately, a Turkish court has blocked access to Grok after it generated responses that the authorities said included insults to President Tayyip Erdogan.

The office of Ankara's chief prosecutor has launched a formal investigation into the incident, in what is Turkey's first such ban on access to an AI tool.

Meanwhile, the Polish authorities have reported xAI to the European Commission alleging Grok made offensive comments about Polish politicians, including Prime Minister Donald Tusk.

Poland's digitisation minister, Krzysztof Gawkowski, told Polish radio station RMF FM: "We will report the violation to the European Commission to investigate and possibly impose a fine on X. Freedom of speech belongs to humans, not to artificial intelligence."