JERUSALEM — An anti-Egypt rally in southern Gaza turned deadly on Wednesday when demonstrators rushed the border fence and stoned Egyptian troops on the other side, leading to an exchange of gunfire and the death of an Egyptian soldier. Nine Egyptian soldiers and a dozen Palestinians were wounded from stones and gunfire, witnesses and medics said.

It was the most serious Palestinian-Egyptian violence along the closed Gaza border since Israel’s short-lived invasion more than a year ago, and it reflected rising tensions between Gaza’s Hamas rulers and the Egyptian government, which, like Israel, appears determined to keep Gaza isolated.

The demonstration, organized by Hamas, protested Egypt’s refusal to allow international aid and solidarity missions into Gaza as well as Egypt’s construction of an underground barrier to obstruct smuggler tunnels. Those tunnels supply both goods and arms to Hamas and Gaza.

As Hamas leaders gave speeches on Wednesday, young men climbed the border fence and threw rocks at the Egyptians, witnesses and the police reported. Palestinian police officers shot in the air to control the crowd, though to little avail. Egyptian troops then shot from their side. “Two Palestinians were instantly wounded from five bullets,” a witness said.

The Egyptian forces also fired tear gas at demonstrators who waved Hamas and Turkish flags, witnesses said. A Palestinian aid convoy was stopped by Egypt in the northern Sinai city of El Arish and included Turkish activists. The group, called Viva Palestina, consisted of 500 people, including Americans, British and Jordanians. It had scuffled earlier with Egyptian security officials in El Arish. Dozens were hurt.

A compromise was reached, and part of the convoy was headed into Gaza by nightfall.

“The area is calm now and the situation on the border is stable,” said Ihab al-Ghussein, spokesman for the Hamas Interior Ministry, at a news conference in Gaza City.

The Egyptian soldier who was killed was in an observation tower 100 yards from the demonstration’s stage, witnesses said.

Dr. Ahmed Shehada of Abu Yousef al-Najjar Hospital in Rafah said the hospital had taken in 12 wounded Palestinians, “most of them hit by gunshots.”

Fares Akram contributed reporting from Gaza.