An explosion on a bus carrying Israeli youth in the Bulgarian resort town of Burgas killed as many as seven people and injured at least 20 at around 5:20 p.m. local time. It's unclear what happened — apparently some are claiming it was a female suicide bomber, while the Israeli Foreign Ministry says it wasn't a suicide bombing but rather a bomb in the trunk — but Bulgaria has been increasing security on resort towns frequented by Israelis since the January discovery of a suspicious package on an Israeli tourist bus.

Israeli Prime Minister Benjamin Netanyahu has accused Iran of the bombing and said that Israel "will retaliate fiercely."

Some have been speculating that the bus was carrying the Israeli under-20 basketball team, in Bulgaria for a tournament; we'll update as more information comes out.