Jaguar Land Rover (JLR) said on Wednesday that a cybersecurity breach disclosed last week had impacted “some data,” disrupting both production and sales at the British luxury carmaker.

The company did not specify what type of data was compromised but confirmed it had notified the relevant authorities.

The British automaker took its systems offline last week to limit the fallout from the breach, compounding existing challenges such as launch delays and weaker demand.

UK media outlets have reported that several groups have claimed responsibility and warned the disruption may persist for weeks, though JLR has neither confirmed nor denied these claims.

Tata Motors, its parent company, did not immediately respond to Reuters’ request for comment.