BRUSSELS (Reuters) -Elon Musk's X social media platform has been hit by complaints by nine civil society organisations to EU and French regulators over what they say is its use of users' data for targeted advertising that may breach EU tech rules.

The organisations - AI Forensics, the Centre for Democracy and Technology Europe, Entropy, European Digital Rights, Gesellschaft für Freiheitsrechte e.V. (GFF), Global Witness, Panoptykon Foundation, Stichting Bits of Freedom and VoxPublic said they took their complaint to the European Commission and the French media regulator Arcom on Monday.

They urged both regulators to take action under the Digital Services Act (DSA) which prohibits advertising based on sensitive user data such as religion, race and sexuality.

X, the Commission and Arcom did not immediately respond to emailed requests for comment.

"We express our deep concern regarding the use by X of users' sensitive personal data for targeted advertisements," the organisations said in a statement.

They said their concerns were triggered after they looked into X's Ad Repository which is a publicly available database set up by companies as part of a DSA requirement.

"We found that major brands as well as public and financial institutions engaged in targeted online advertising based on what appear to be special categories of personal data, protected by Article 9 of the GDPR, such as political opinions, sexual orientation, religious beliefs and health conditions," they said.

The group called on the regulators to investigate X. GDPR refers to the EU data privacy law.