Gaza medical officials said the boy, Yasser Abu Al-Naja, 14, and Mohammad Al-Hamayda, 24, were hit by live bullets. They added that four other men wounded by live fire were in critical condition.
The Israeli military had no immediate comment on Friday’s protests and a spokesman said a statement would be issued later. Gaza officials say Israeli troops have killed at least 135 people since the weekly protests began on March 30.
Palestinians say the protests are a popular outpouring of rage against Israel by refugees demanding the right to return to homes their families fled or were driven from on Israel’s founding 70 years ago.
Israel says the demonstrations are organised by the Islamist group Hamas that controls the Gaza Strip and denies Israel’s right to exist. Israel says Hamas has intentionally provoked the violence, a charge Hamas denies.
Tens of thousands took part when the protests were launched at several locations along the Gaza border but the number has dropped significantly in the past few weeks and only a few thousand have participated more recently.
Israel’s deadly tactics have drawn international condemnation. But support has come from its main ally, the United States, which like Israel, has cast blame on Hamas.
Israel has accused Hamas of stoking the violence in an attempt to deflect domestic opinion from Gaza’s energy shortages and faltering economy.
Israel maintains a naval blockade of Gaza and tight restrictions on the movement of people and goods at its land borders. Egypt has also kept its own Gaza frontier largely closed. Both countries cite security concerns for the measures, which have deepened economic hardship.