The nation did the same three days ago, when three Syrian army tanks entered the Golan Heights demilitarized zone, according to the Israeli military. The tanks were positioned with their guns pointing toward Syria and fired, Israel said.
A U.N. observer force remains in the Golan Heights to maintain a cease-fire between the Israeli and Syrian forces and to oversee implementation of the disengagement agreement. Israel's government controls the Golan, though some internationally regard it as occupied territory.
The Syrian civil war has spilled over into other countries as well, including Lebanon and Turkey. Stray shelling from Syria into southern Turkey has caused several deaths in recent weeks, ratcheting up tensions between the one-time allies and spurring Istanbul to order the firing of artillery rounds back into their neighbor's territory.
Syria's opposition groups began a second day of negotiations Monday in Qatar's capital city of Doha as part of an effort to unify the rebellion.
The move comes after reports that U.S. Secretary of State Hillary Clinton told reporters that the exiled Syrian National Council should no longer be considered the "visible leader" of efforts to form a government to replace al-Assad, whose iron-fisted attempt to crush anti-government protests has resulted in the bloody civil war.
Clinton said the opposition must include seats for "those who are on the front lines fighting and dying today."
The United States has recommended people and organizations that should be included, she said -- and the State Department says Robert Ford, the U.S. ambassador to Syria, will be "on the sidelines" of the upcoming Doha talks.
The U.S. secretary of state's remarks drew criticism from some opposition activists Monday. In a statement, the opposition Local Coordination Committees of Syria said they represented unwelcome "interventions in the affairs of the revolution."
State Department spokeswoman Victoria Nuland said Monday that the United States does not intend to pick Syria's next leaders.
"Only Syrians can do this," she told reporters, "so, none of the activities that we've been involved in since the last months and months are designed to do that. They're simply designed to insure that those Syrian voices inside Syria...are heard and are part of the process."
French President Francois Hollande made a similar statement Sunday, saying that the Syrian opposition needs a leader to set up "an interim government through a fair democratic process," the state-run Saudi Press Agency reported.
The negotiations in Doha began after the SNC announced it would elect a new president, replace half of its executive board and expand its membership. The SNC says its meetings are a prelude to talks with other opposition groups later this week.
"Any discussion about bypassing the SNC or forming other alternative entities is an attempt to damage the revolution and sow the seeds of division and discord," the group said in a statement.