Death toll rises in Israel-Gaza border unrest: reports
Mounds of tyres were set alight to launch the second week of demonstrations.
At least 22 Palestinians have died since protests near the Gaza border fence began on March 30, according to the Palestinian health ministry in Gaza.
Tens of thousands of Palestinians are holding a six-week-long protest in tent encampments along the fenced border of the Israeli-blockaded Gaza Strip.
But large groups have ventured much closer to the no-go zone along the border, risking live fire from Israeli troops.
The protesters, including Palestinian refugees and their descendants, are seeking to regain homes in what is now Israel that were lost during its 1948-1949 independence war.
However, Israel has accused Gaza's Hamas rulers of using the protests as a cover for attacking Israel's border.
In a statement on Friday, the Israeli military said rioters had "attempted to damage & cross the security fence under the cover of smoke from their burning tires."
It said it was responding with "riot dispersal means, including water cannons to put out fires, a huge fan to disperse the smoke, and fire in accordance with the rules of engagement."
The United Nations earlier on Friday called on both sides to refrain from violence.
"I call upon all parties on the ground to avoid confrontation and exercise maximum restraint. I particularly urge Israel to exercise extreme caution with the use of force in order to avoid casualties. Civilians must be able to exercise their right to demonstrate peacefully," said UN Secretary General Ant'onio Guterres.