Brussels has opened an investigation into Snapchat over concerns that the social messaging app is exposing children to grooming, sexual exploitation and other criminality.

In a separate decision on Thursday, the European Commission also said four pornographic websites were failing to prevent minors seeing adult content.

The investigations into five tech companies were brought under the EU’s Digital Services Act (DSA), which has come under fire from Donald Trump since coming into force two years ago. Aiming to protect European society from a wide-range of internet harms, the DSA includes child safety provisions to combat cyberbullying, exposure to adult content and illegal products.

The announcements came after a landmark ruling in a Los Angeles court found that two social mediacompanies, Meta and YouTube, had deliberately created addictive products that harmed a young user. The EU is weighing whether to follow Australia and ban social media for the under-16s,

Opening its first case against Snapchat, the commission said it suspected the messaging app was allowing its services to be misused by adults, who pretended to be minors to lure children into sexual exploitation and other criminal activities. Regulators also fear the app is a source of information about drugs and age-restricted products, such as alcohol and vapes.

Snapchat reports 94.7 million monthly users in the EU and is hugely popular among teens and young people.

Under Snapchat’s own terms and conditions, users must be at least 13 years old. But EU regulators believe the company is failing to ensure this age limit is respected. They also believe users are not given adequate guidance on privacy and safety features, while mechanisms to report illegal content are not user-friendly.

The latest decision means EU regulators will carry out a detailed investigation and can order the company to take preventive steps to protect children, pending any final decision.

In response, a Snapchat spokesperson said the safety and wellbeing of their users was a top priority. “Snapchat is designed to help people communicate with close friends and family in a positive, trusted environment, with privacy and safety built in from the start – including additional protections for teens,” the spokesperson said. “As online risks evolve, we continuously review, strengthen, and invest in these safeguards.”

In a separate announcement on Thursday, the commission accused four pornographic websites, Pornhub, Stripchat, XNXX and XVideos, of failing to prevent children from accessing adult content.

After an investigation launched last May, the commission concluded the four websites “did not diligently identify and assess the risks that their platforms pose to minors”. To access the sites, children and young people could simply click a button saying they were over 18, a self-declaration system deemed ineffective by EU regulators.

The companies may now examine the findings, before any final decision is taken.

They could end the investigation by producing forms of age verification deemed effective by EU regulators. But if the complaint is upheld the four websites could be fined up to 6% of global annual turnover.

The parent companies of Pornhub and Stripchat were approached for comment. A Brussels-based lawyer who appears to have previously represented the parent companies of XVideos and XNXX in EU legal proceedings was also contacted for comment.