JERUSALEM - Following the deadly clashes on Sunday with pro-Palestinian protesters at the Israeli-Syrian ceasefire line, the Israeli army on Monday prepared for more similar demonstrations.

The clashes happened when the Israeli army opened fire to prevent some of the Syrian protesters from crossing the ceasefire line. More than 20 people were killed and some 300 others were wounded, according to a press release by the Syrian Health Ministry.

The Israel Defense Forces (IDF) said that they used limited live fires after the protesters ignored the repeated warnings.

Israel has beefed up its security forces along the Golan Heights ceasefire line, while around a hundred protesters still linger on the Syrian side as of Monday, Ha'aretz daily reported.

The Israeli army estimated on Monday that Palestinian refugees will continue their efforts along the border in the following days.

"We must remain alert and prepared," said IDF Chief of the General Staff Benny Gantz, who on Monday visited units stationed along Israel's northern border.

"The IDF is prepared to use all the defensive means at its disposal to prevent large scale attempts to breach the border," he said, according to an IDF statement.

Israel is considering to file a complaint with the United Nations against what it said was Syria's incitement of border violence, local media reported on Monday.

The complaint cited what Israel charged was Syria's unwillingness to restrain the protesters. The complaint focused on Syria's "manipulation of its own citizens to generate violent incidents at the border," a government official told Ha'aretz.

While the Syrian Foreign Ministry on Monday slammed Israeli army's response to the protest, calling it the "fierce aggression conducted by Israel on unarmed Palestinian and Syrian protesters." The ministry said in a statement that the victims were demanding their natural and legal right to return to their own homeland in the territories occupied by Israel.

Hundreds of Syrian protesters gathered near the ceasefire line with Israel before the deadly clashes on Sunday, the Palestinian Naksa Day which commemorates the outcome of the 1967 war when Israel came into control of the Golan Heights, the West Bank, East Jerusalem and the Gaza Strip.

The situation calmed down on Monday, despite scores of protesters still rallied on the Syrian side near the Golan Heights village of Majdal Shams, one of the most serious clashing site one day earlier.