Russians hackers have logged into private security cameras in Ukrainian coffee shops to collect intelligence on aid convoys passing by, a top US security official said on Tuesday.

Rob Joyce, director of cybersecurity at the National Security Agency, said the Russian government and government-backed hackers persist in attacking Ukrainian information technology systems as part of their invasion of the country.

One focus is closed circuit TV cameras used by local authorities and private businesses to monitor their surroundings, he said.

“There are continued attacks on Ukrainian interests, whether it’s financial, government, personal, individual business, just trying to be disruptive,” Joyce said at the Center for International and Strategic Studies in Washington.

“There are creative things going on. We are watching the Russian hackers log into public-facing webcams to watch convoys and trains delivering aid,” he said.

“They are also hacking those webcams … And instead of using the town square (cameras) that are available to the internet, they’re looking at the coffee shop security camera and seeing the road they need to see,” he said.

Russians are also focusing their hacking efforts on US defense manufacturers and logistical transport companies to find out more about the arms supply chain to Ukraine, he said.

“They are under daily pressure from the Russians,” he said.