Israeli troops at a border crossing with Jordan came under fire on Tuesday, says the Israeli military, but Jordan denies any fire came from the kingdom.
"Troops were fired on from the Jordanian side of the border. It was unclear who the gunmen were," says an Israeli spokesperson.
The troops, stationed at the Arava border crossing in southern Israel, returned fire, the spokesperson said. No Israeli troops were hurt.
On Sunday, Israeli troops in the Golan Heights came under fire from Syria.
Jordan rejected the claim, saying: "There is no truth to this information."
Jordan signed a peace treaty with the Jewish state in 1994, becoming the second Arab state to do so, after Egypt.
Most of Jordan's 5 million citizens are of Palestinian origin, they or their parents having been expelled or fled to Jordan in the fighting that accompanied the creation of Israel in 1948.