Some Japanese research institutions developing coronavirus vaccines have been hit by cyberattacks, apparently from China, in what are believed to be the first cases of their kind in the country, a U.S. information security firm said Monday.

Amid an intensifying race to develop vaccines against COVID-19, those bodies have been targeted by attacks since April but no reports of information leaks have been made, according to CrowdStrike.

The government’s National Center of Incident Readiness and Strategy for Cybersecurity has urged drugmakers and research organizations to raise alert levels against such attempts to steal confidential information.

The U.S. firm did not disclose the names of the targeted institutions, but said it suspects the attacks have been made by a Chinese hacker group, based on the techniques employed.

The attacks involved sending emails attached with electronic files, which seemed to be related to the new virus but contained computer viruses, according to the company.

In Japan, the University of Tokyo, Osaka University and the National Institute of Infectious Diseases, among others, have joined the race.

The government-sponsored Japan Agency for Medical Research and Development, or AMED, which allocates state funds to support medical research, has adopted 20 vaccine projects conducted by universities and private companies.

Major pharmaceutical firms, including Takeda Pharmaceutical Co. and Daiichi Sankyo Co., have been selected for the agency’s support scheme for COVID-19 vaccine development, which grants up to Â¥10 billion to each project, according to AMED.

But it is still unknown when the first domestically developed COVID-19 vaccine will see widespread use, while some foreign countries aim to introduce their own by the end of the year.