An estimated 30,000 Palestinians moved towards the Israeli security fence along the Gaza Strip on Friday, with attackers and rioters throwing gas bombs, Molotov cocktails and rocks, in addition to burning tires.

The protesters descended on the fence that separates Gaza and Israel as part of the “March of Return” and “Land Day” demonstrations organized by Hamas. According to the Hamas-run Gaza Health Ministry, 12 demonstrators have been killed and more than 1,200 were injured by Israeli rubber bullets, tear gas and some live fire. The Israel Defense Forces did not confirm the Gaza Health Ministry’s figures.

The IDF said that only those who were attempting to breach the border fence were targeted with live fire.

”In every spot where there were cases of Palestinians attempting to cross or harm the fence, IDF troops returned precise fire,” IDF spokesperson Brig.-Gen. Ronen Manelis told The Jerusalem Post. “Live ammunition was used only against those attempting to harm the fence.”

IDF reports indicate that organizers of the demonstration are deliberately placing civilians in harm’s way, citing an incident in which a 7-year-old girl was made to march towards the security fence in an attempt to draw Israeli gunfire. Israeli troops spotted the girl and ensured that she was not injured.

“The Hamas terror organization cynically exploits women and children, sending them to the security fence and endangering their lives,” the IDF said in a statement.

The IDF assured the public that it would not allow rioters to “violate Israel’s sovereignty” by breaching the security fence. It also flew airplanes over Gaza, dropping leaflets warning Palestinians not to try to breach the security border. The same message was also put out over social media and as statements to news outlets.

“We’re identifying attempts to carry out terror attacks under the disguise of riots. We urge Gazans to stay away and warn the Hamas terror organization,” said GOC of the IDF’s Southern Command, Maj. Gen. Eyal Zamir.

Earlier on Friday, the army stationed additional forces and more than 100 snipers along the border to prevent infiltration. A second line of defense was also posted along the south in case a mass infiltration attempt succeeded.

The IDF said it held Hamas responsible for inciting the population to violence, also noting that it was therefore to blame for any injuries to Gaza protesters.

“Those who approach the fence today are putting themselves in danger,” Defense Minister Avigdor Lieberman said in a post on social media. “I would advise [Gazans] to go on with your lives and not engage in provocations.”

Khaled al-Batsh, leader of the Islamic Jihad terror group in Gaza, said that Palestinians were demanding to return to lands inside Israel. “Seventy years ago we left, and today we have decided to return to our country,” he told AFP.

The Palestinians have consistently argued that they are refugees since Israel’s 1948 War of Independence, and have demanded that the status extend to their children and grandchildren, though international law does not support the inheritance of refugee status.