A unit of General Dynamics, Spain-based Santa Barbara Systems, which is refurbishing Leopard tanks for delivery to Ukraine, suffered a cyber attack that took its website down, a pro-Russian hackers group said.

A spokesperson for General Dynamics in Germany said the defense contractor was still analyzing the cause of the website outage, adding that all of its operations in Europe were running normally.

The NoName hacking group on the Telegram messaging service claimed responsibility for the distributed denial-of-service (DDoS) attack.

DDoS attacks direct high volumes of internet traffic toward targeted servers to knock them offline.

"We sent our DDoS-missiles against websites in russophobic Spain," the group, which often directs such actions against countries which support Ukraine, wrote on Telegram on Tuesday.

NATO said last month that Russia was behind an intensifying campaign of hybrid attacks on companies and infrastructure in member states, an accusation Russia dismissed as "misinformation."

Santa Barbara assembles heavy vehicles such as Leopard tanks and artillery equipment for the Spanish army and has been involved in refurbishing Spain's mothballed Leopard tanks for delivery to the Ukrainian army, according to the Defense Ministry.

Spain last week pledged 1 billion euros ($1.08 billion) in military support for Ukraine this year, which according to local media reportscyber includes 19 Leopard 2A4 tanks.