Among the seriously wounded is a 13-year-old Palestinian boy and Israeli police.
Israel has carried out air strikes on the Gaza Strip, which has been under blockade for more than a decade, according to the French news agency AFP, citing its Palestinian source of security. The Israeli Armed Forces says On Twitter hit four targets.
Both report that the targets were targets linked to the extremist organization Hamas.
Earlier on Saturday, dozens were injured or wounded in a clash between Israeli forces and protesters on the Israeli-Gaza border. Among the seriously wounded is a 13-year-old Palestinian boy and Israeli police.
In May, Israel and the extremist organization Hamas agreed on a ceasefire after 11 days of hostilities. At least 260 Palestinians and 13 Israelis died during them.