Japan’s largest advertising agency, Dentsu Group Corp., has evacuated its Tokyo headquarters after receiving a bomb threat, an internal company email reviewed by Reuters showed on Friday.

The company, in an email to employees, cited a message sent to its website, saying: “Warning of explosion at Dentsu’s Shiodome headquarters building with deadline past 7:00 a.m. on June 7, Sunday.”

Dentsu confirmed it has closed the building due to a bomb threat, and said it has notified the authorities.

Entry to the building was forbidden over the weekend, the company said in the email. Dentsu had already introduced work-from-home measures because of the coronavirus outbreak.

The company is the focus of political scrutiny having been awarded almost $700 million (77 billion yen) in government funds to help run a coronavirus aid program via a scheme that has been described as opaque.

Dentsu’s headquarters is in the Shiodome business district, where blue-chip Japanese firms including tech conglomerate SoftBank Group Corp. and airline ANA Holdings are also based.