Egypt’s armed forces said they were investigating a shooting incident in the Rafah border area Monday that killed a member of its security forces — underscoring the risk of spillover from the Gaza war and putting further strain on Cairo’s relations with Israel.

The Israel Defense Forces confirmed a “shooting incident at the Egyptian border” and said it was also investigating. “A dialogue is underway with the Egyptians,” the IDF added in a statement. Neither Egypt nor Israel said who opened fire first.