Canadian Defence Minister Anita Anand said on Saturday that the country’s critical infrastructure was increasingly being targeted by cyberattacks, posing a significant threat to the economy of the world’s fourth-largest crude oil producer.

The U.S. State Department warned last month that China was capable of launching cyberattacks against oil and gas pipelines and rail systems, after researchers discovered a Chinese hacking group had been spying on such networks.

In an interview on the sidelines of an Asian security summit in Singapore, Anand said there had been an increase in cyberattacks across North America, although she did not attribute the strikes to any state-sponsored actors.

“We have seen attacks on critical infrastructure in our country and we are very conscious to advise Canadian organisations and Canadian companies to take mitigation measures,” Anand said.

“The risks can be substantial to our economy and systems that are protecting the lives of our citizens.”

Canada is home to a number of large oil pipelines that are important for global crude supplies. Multinational energy companies like Exxon Mobil and Royal Dutch Shell have major operations in the country.

Anand was speaking at the Shangri-La Dialogue, Asia’s top security meeting, where rising tensions between the United States and China have dominated proceedings.

Chinese military officials have accused the U.S. and its allies of using the conference to gang up on Beijing and open divisions in the Asia-Pacific region.

“We have to be eyes wide open on China. They have become an increasingly disruptive global power,” Anand said when asked about China’s complaints.