HORSENS, Denmark — The European Commission is probing two platforms and two app stores about their compliance with EU digital regulations designed to protect minors.

The Commission has sent requests for information to Snapchat, YouTube, Apple Store and Google Play on how they protect kids on their platforms under the Digital Services Act, the Commission’s Executive Vice President Henna Virkkunen said in Denmark Friday.

All four are designated as Very Large Online Platforms under the regulation because they have more than 45 million users in the European Union, so they have to follow strict risk assessment and mitigation provisions.

The requests are a first step in the enforcement process — should the Commission suspect a breach after the platforms respond, it can open formal investigations.

If companies are found to have breached the regulation, they can be fined up to 6 percent of their annual global revenue.

Virkkunen declined to give further details on the requests at this time.

EU ministers have gathered in Horsens, Denmark, to discuss the protection of children online, a top priority for Copenhagen and several other countries.

The EU executive already has open DSA investigations on minors’ protections looking into major porn platforms as well as Meta and TikTok.