Advertising agency Dentsu Group Inc. evacuated its headquarters in Tokyo Friday after a bomb threat was made, with security guards cordoning off the building and commercial facilities in the vicinity.

The threat against the head office was made as a posting on the company's website, Dentsu said. The message with a personal name said, that "a bad company that disturbs the world will be disciplined," an informed source said.

File photo taken May 15, 2020, shows the Tokyo headquarters of Dentsu Inc., Japan's largest advertising agency. (Kyodo)

The message also said the bomb will detonate at 7 a.m. on June 7, according to police, which searched the building but found nothing suspicious.

Dentsu has recently come under criticism for involvement in allegedly shady dealings in the government's cash benefit program for small companies hit by the new coronavirus outbreak.

"We alerted the customers in the shopping and restaurant area (of the building), as well as Dentsu employees around 2 p.m. to leave the building," said a security guard who declined to be named.

The ad agency is based in the Shiodome business and leisure district near Tokyo Bay, marked by office towers, shopping centers, and high-rise hotels.

Companies including Shiseido Co., ANA Holdings Inc., Nippon Television Network Corp. and Kyodo News have their headquarters in the area.

Dentsu said it has tightened security in the 48-story office building and around the area, with entry to the building and facilities around the area prohibited. About 20 percent of its employees at the headquarters currently work in the building while others are working from home as a measure to prevent further spread of the new coronavirus.

"I wanted to buy boxed lunch at the convenience store inside the building," a 49-year-old man working for an energy company in the Shiodome area said. "But I was told by a security guard that I could not go inside. I heard some people in my office talking about a bomb threat as they had seen the news on the internet."

An organization, believed to be set up by Dentsu and two other companies, won the bid for the government's cash benefit program for small and medium-sized companies hit by the coronavirus at 76.9 billion yen ($712 million) and then recommissioned the work to handle applications from businesses to Dentsu for 2 billion yen less.

The board of the council of the organization, Service Design Engineering Council, consists of eight part-time members, including those linked to Dentsu, Pasona Group Inc. and Transcosmos Inc.

Opposition parties criticized the process, as the work could have been directly consigned to Dentsu at a lower price.

Dentsu then consigned the work to temporary staffing service Pasona and Transcosmos, which provides integrated marketing, outsourcing and call center services.

The ad agency has told Kyodo News it is carrying out the program in line with a government manual, and there is no problem with its implementation.