The superintendent-general of the Metropolitan Police Department has called for public cooperation in keeping the capital safe during the Group of Seven summit in Mie Prefecture later this week.

"If you notice anything suspicious, please call the police immediately," Superintendent-General Kiyotaka Takahashi said Saturday while visiting the glitzy Ginza shopping district to inspect security there.

Authorities have tightened security in Tokyo as well as Shima, the city that will host the two-day G-7 leaders' meeting starting Thursday.

Although Tokyo is far from the summit venue, the police are out in force to prevent terrorism from interfering with the event.

Citing what happened earlier this year in Paris and Brussels, where terrorists attacked crowded places with relatively loose security, police sources warned that Tokyo has many similar places.

On Saturday, police began restricting entry to Kashikojima Island in Shima. The Kashikojima Ohashi Bridge, one of the two linking the mainland to the resort island where the leaders will meet in Ago Bay, was shut down because it is situated close to a hotel at the venue for the Ise-Shima summit. For vehicles coming to the island via the other bridge, Kashikojima Bashi, police set up security checkpoints nearby where metal detectors are being used.

The Kashikojima Ohashi Bridge will be closed until the morning of May 28, the Mie Prefectural Police said.

Meanwhile, railway Kintetsu Corp. suspended the Kashikojima-Ugata section of the Shima Line on Saturday, while waters surrounding the island were declared off-limits to ships and boats, with the exception of those run by pearl farmers, who will be allowed entry after undergoing security checks.

The cordoning off of the venue will be complete when the 46-km no-fly zone takes effect on Wednesday.