A suspected perpetrator has been killed by Israeli security forces, according to the police.
"We found three men lying unconscious, without a pulse and not breathing, with gunshot wounds," writes the rescue service Magen David Adom in a press release.
"Together with the Israeli military's medical personnel, we attempted to resuscitate them, but unfortunately, we were forced to declare them dead on the spot."
The men, all in their 50s, worked as security guards at the border crossing, according to Israel's military.
Jordan's authorities are investigating the incident, reports the country's state news agency Petra. The border crossing is used by Palestinians, Israelis, and international tourists.