Google, Facebook, and Twitter have agreed to delete hate speech deemed illegal in Germany within 24 hours, following pressure from German authorities who have become concerned about an increasing number of racist comments being posted on social media.

The companies committed on Tuesday to removing “illegal content promptly, that is, within 24 hours,” Justice Minister Heiko Maas said, as quoted by AFP.

"Complaints will be examined by specialist teams. And the benchmark to be applied will be German law and no longer just the terms of use of each network," Maas added.

The three internet giants and the Justice Ministry said in a joint statement on Tuesday that the social networking sites will also make it easier for users and anti-racism groups to flag hate speech posted online. Maas added that a monitoring mechanism will be put in place to review whether the system is working.

The justice minister stressed that the measures are not intended to curtail free speech, but rather to ensure German law is applied online.

The move follows pressure put on the US companies in Germany to take action after the number of xenophobic and racist comments has surged online. Concern escalated after the far-right began to take aim at the record number of refugees arriving in Germany this year, with Maas stating that social networks must not “become a funfair for the far-right.”

However, critics have slammed Maas, claiming he has failed to achieve what he set out to do when he announced the creation of a joint “taskforce” to fight hate speech.

"Maas has buckled in the face of Facebook and Co.," Green party leader in the Bundestag (German parliament) Katrin Göring-Eckhardt told Spiegel Online. "[He] called far-right crimes shameful, but it's almost exactly as shameful that his ministry is doing nothing against online hate."

The justice minister had initially demanded that a German-speaking team be put together at Facebook, though there is no sign that the request will be met.

In addition, Facebook will not publish data on the numbers of messages it removes or the proportion of messages reported as abusive which were ultimately taken down – another of Maas' original demands.

Instead, the three social network sites will only be required to ensure "transparency by reporting to the public how it implements its terms of use with relation to removing reported content," according to the terms of the agreement with Maas.

Germany has strict laws against the expression of racial hatred, a reaction to the country's Nazi past.