Twitter suspended the accounts of several prominent journalists who had posted about its new owner Elon Musk, prompting protests from their media organisations.

"Press freedom cannot be switched on and off on a whim," the ministry wrote on its official Twitter account. "The journalists below can no longer follow us, comment and criticise. We have a problem with that, @Twitter."

Twitter did not immediately respond to a request for comment.

German regulators are already pushing government institutions to stop posting announcements exclusively to privately-held platforms, touting alternatives like the fledgling decentralised social media network Mastodon.

A government spokesperson later told a regular news conference that the government was monitoring developments on the Twitter platform with growing concern.

Twitter also suspended the Mastodon network's account and attempts to link to Mastodon accounts in tweets frequently triggered error messages on Friday.

Mastodon's new user registrations soared to as high as 4,000 an hour on Friday morning, four times the rate seen over the past week. But with some 8.5 million registered users, Mastodon is still a minnow compared to Twitter with half a billion users.

A spokesperson for British Prime Minister Rishi Sunak also responded to questions about the journalists' suspensions, saying social media platforms had to balance protection of users with preservation of free speech.