The fires have disrupted daily life in communities near the Gaza Strip.
In a statement later on Friday, Hanan Ashrawi, Palestinian Liberation Organization executive committee member, said the USA had once again demonstrated its "blind loyalty to Israel and tried to absolve it of any wrongdoing despite its egregious violations, deliberate massacres and willful killings and war crimes".
There was no immediate comment from Palestinian officials on the incident, which comes at a time of renewed violence along the Israel-Gaza frontier.
Residents said al-Najar was a popular figure at the protest sites and pictures depicting her as an angel circulated on Palestinian social media.
Israel and Hamas have fought three wars since the Islamic militant group seized control of Gaza in 2007.
Since March 30 Israeli troops have killed at least 120 Palestinians during mass demonstrations along the Gaza border, drawing worldwide condemnation.
Palestinian protesters in Gaza have been flying flammable kites to set Israeli fields ablaze after Israeli troops responded with deadly force to weekly Friday protests on the border.
The IDF, in response, used tear gas and live fire against the demonstrators, reportedly killing a 21-year-old female paramedic, Razan Najjar.
Israel, which has drawn global condemnation for its use of deadly force, says many of those killed were Hamas members and militants trying to launch attacks under cover of the protests.
Since nonviolent protests began at the end of March, Israeli soldiers have killed at least 119 people, including 14 children.
Since the beginning of the Great March of Return protests in the Gaza Strip, Israel has killed more than 100 Palestinians and injured thousands more.
Last week, residents in Gaza attempted to break a 12-year crippling siege that has trapped more than two million Palestinians since 2006.
The demonstration took place on the same day as the United States moved its embassy in Israel in Jerusalem, a move that was widely denounced as recognising Israel's claims to the city as its capital to the detriment of Palestinian claims to Jerusalem.
He said that most of the reporting of events on the Gaza border in recent weeks was "completely superficial" and "had no basis in fact".