JERUSALEM — An Israeli airstrike in the southeast Gaza Strip on Tuesday morning killed three Palestinian militants who the Israeli military said had fired a mortar at its soldiers patrolling near the border, hours after a pilotless Israeli surveillance drone crashed nearby.

The two unrelated incidents in Gaza, where an uptick in cross-border violence over the past two months has threatened a fragile cease-fire with Israel, came amid growing outrage over Monday’s fatal shooting by an Israeli soldier of a Jordanian judge of Palestinian origin at the Allenby Bridge, which links Jordan and the West Bank.

Even before the Gaza airstrike, Nabil Abu Rudeineh, a spokesman for President Mahmoud Abbas of the Palestinian Authority, issued a statement that condemned Israel for “a dangerous escalation that will lead to the destruction of what remains of the peace process” and could lead to “pushing toward dangerous situations that couldn’t be controlled.”

In Jordan, several hundred protesters called for the ouster of the Israeli ambassador and the cancellation of Jordan’s 20-year-old peace treaty with Israel during a march from a courthouse to the Parliament.