An emergency evacuation order was issued at an international school in Tokyo's Shibuya Ward on Thursday afternoon after a bomb threat was received.

About 800 people evacuated from the British School in Tokyo and neighboring buildings due to a phone call in which a male voice speaking a foreign language threatened to bomb the school, according to TV Asahi.

One parent arrived at 2:50 p.m. to pick up their child and saw several hundred people standing in the street amid the ringing of an emergency bell.

"They had a fire drill like a week before, and (people) went to the same evacuation spots. So I thought maybe it's a fire drill," the parent said. "But when I asked what was going on, then they said 'it's not a drill.' "

A junior high school student who attends Shibuya Junior and Senior High School, which adjoins the international school, said he knew something extraordinary was happening when he heard an emergency announcement at around 3 p.m. asking people to stay inside the school.

About 15 minutes later, he was told by his teacher to return home immediately due to a bomb threat at the international school.

"I asked police, 'Is it true there was a bomb threat?' and was told, 'Yeah, it's real,' " he said via Twitter.

Both the British School in Tokyo and the Shibuya Police Station declined comment.