The European Commission opened formal proceedings on Tuesday against social media firm TikTok over its suspected failure to limit election interference, notably in the Romanian presidential vote last month.

The Commission said it will request information and look into TikTok’s policy on political advertisements and paid-for political content as well as TikTok’s systems to generate recommendations and the risks of them being manipulated.

The opening of formal proceedings empowers the Commission to take further enforcement steps and to accept commitments made by TikTok. There is no specific deadline to complete proceedings.

China’s Bytedance-owned TikTok said it had protected the integrity of its platform through more than 150 elections worldwide and had provided the European Commission with extensive information on its efforts.

It added it did not accept paid political advertisements and pro-actively removed content violating its policies on misinformation and hate speech.

The Commission ordered TikTok on Dec. 5 to freeze data linked to the Romanian elections under the bloc’s sweeping Digital Services Act (DSA), which regulates how the world’s biggest social media companies operate in Europe.

Romania’s top court subsequently annulled the presidential election after accusations of Russian meddling and the victory of pro-Russia ultranationalist Calin Georgescu in the first round.

The Commission is conscious of the risk of interference in the German parliamentary election in February and the presidential election in Croatia starting on Dec. 29.

Commission President Ursula von der Leyen said the new investigation followed serious indications that foreign actors interfered in the Romanian presidential election.

“We must protect our democracies from any kind of foreign interference. Whenever we suspect such interference, especially during elections, we have to act swiftly and firmly,” she said in a statement.

This is the third investigation the Commission has launched against TikTok under the DSA, both related to risks for minors. One has been closed after TikTok committed to remove TikTok Lite Rewards from the EU.