Britain warns over threats to Tokyo schools

Japanese authorities said Thursday they were investigating threats to kill young children in central Tokyo, which led the British embassy to issue a warning to its nationals.

Six elementary schools in Tokyo's Minato ward received letters in July threatening to kill children, a municipal official said.

"We immediately reported the case to police and they are investigating," said Hiroshi Takijima, an official in the ward's government.

The schools went on summer vacation on July 19 but teachers and parents are still patrolling around the schools, he said.

The threatening letters were typed on a computer and listed the name of a sender, he said.

Minato ward includes Roppongi, an area popular with foreigners known for its nightlife, as well as upscale residential areas.

The British embassy posted a warning on its website advising its nationals who live in the ward to "exercise caution until this matter is resolved."

Japan has one of the world's lowest crime rates but has seen a series of grisly attacks against children.

In one of the most notorious cases, a former psychiatric patient went on a stabbing spree at an Osaka elementary school in 2001, killing eight children with a butcher's knife.