BERLIN (AP) — German officials are stepping up their criticism of Facebook, saying the social network is doing too little to stop hate speech and could face stiff fines unless it deletes illegal content faster.

In an interview published Friday, Justice Minister Heiko Maas said his ministry was checking whether it would be possible to make social networking sites legally liable for illegal posts.

“Of course in the end, we also have to think about fines, if other measures fail to work,” Maas told the Sueddeutsche Zeitung newspaper. “That would be a strong incentive to act quickly.”

Germany has seen a sharp increase in vitriolic posts on social media in recent years amid a heated public debate over the influx of more than a million migrants since the start of 2015.

The country has laws against speech deemed to be racist, defamatory or inciting violence — a response to Germany’s Nazi legacy. But authorities have struggled with the deluge of often anonymous postings on foreign-owned websites.

Facebook, based in California, says it takes the issue seriously and has hundreds of contractors reviewing posts at a Berlin office. But Sueddeutsche Zeitung reported Friday that staff members there complain of inconsistent rules and overwork .

Thomas Oppermann, a senior lawmaker in Maas’ Social Democratic Party, told German weekly Der Spiegel that dominant social media sites like Facebook could be required to delete illegal posts within 24 hours or face fines up to 500,000 euros ($522,000).

Facebook also could be compelled to distribute corrections that reach the same number of people as the original post, Oppermann suggested, something traditional media companies in Germany are already required to do.

The proposals come as German officials warn that the country’s upcoming general election is likely to be heavily affected by hate speech and fake news spread on social media.

The nationalist Alternative for Germany party, which has a strong presence on Facebook, criticized the government’s proposals as an attempt to limit free speech.