Syria's Assad is now in Moscow, Russian state media says

Israeli Prime Minister Benjamin Netanyahu weighed in Sunday on the fall of the Assad regime in Syria, calling it a "historic day" in the Middle East.

Netanyahu said that due to Syrian troops abandoning their positions in the buffer zone between Israel and Syria, the Israel Defense Forces has seized those positions.

"We will not allow any hostile force to establish itself on our border," Netanyahu said.

Netanyahu and Defense Minister Israel Katz on Sunday visited Mount Bental in the Golan Heights, an observation point toward the Syrian border.

"This is a historic day in the history of the Middle East," Netanyahu said. "The Assad regime is a central link in Iran's axis of evil -- this regime has fallen."

Netanyahu claimed the fall of Syrian President Bashar al-Assad was a "direct result" of the blows Israel has inflicted on the main supporters of his regime, Iran and Hezbollah.

"This has created a chain reaction throughout the Middle East of all those who want to be free from this oppressive and tyrannical regime," Netanyahu said.

-ABC News' Victoria Beaule

Syrians poured into the streets of Aleppo on Sunday, celebrating the fall of President Bashar al-Assad in a surprise rebel offensive that started 11 days ago.

"An indescribable feeling, without injustice and forbidden things. Things that were forbidden to us only," Aleppo resident Alaa Mayo told ABC News. "We had war, beatings, imprisonment... And our rights, we won't obtain them like the rest of the world."

In Damascus, celebratory gunfire accompanied celebrations since the rebels' overnight takeover of the Syrian capital city. Video showed citizens celebrating in Damascus' Umayyad Square.

ABC News' Camilla Alcini

Pentagon Press Secretary Maj. Gen. Patrick Ryder said Sunday that the U.S. is monitoring the evolving situation in Syria, where rebel forces have seized Damascus and President Bashar al-Assad's government has collapsed.

"The mission of U.S. forces remains unchanged and focused on the 'Defeat-ISIS' mission," Ryder said. "As always, we maintain the inherent right of self-defense and will take necessary steps to protect our service members deployed to the region."
There are around 900 U.S. troops deployed in eastern and northeastern Syria.
-ABC News' Cindy Smith

Israel Defense Forces officials told ABC News that Israel is trying to prevent "strategic abilities" of the fallen government from falling into the hands of rebels now consolidating control after toppling President Bashar al-Assad.

The officials said the IDF struck several "significant" military capabilities and "key weaponry" in Syria "posing a threat to Israel" in recent days.

The IDF officials would not comment on the exact nature of the assets being attacked. Two other regional sources said the targets were related to Syria's residual chemical weapons program, ballistic missiles, aircraft and other advanced assets.

The IDF officials also confirmed that Israeli troops of the 98th Division -- which includes a commando brigade, a paratrooper brigade and specialized infantry units -- were deployed in several locations inside Syrian territory close to the Israeli border.

The units are there to prevent extremists from entering a buffer zone between the two countries originally established in a bilateral 1974 agreement, the officials said. The deployment is intended to be temporary, but the IDF remains in readiness "for all scenarios," the officials said.

-ABC News' Dana Savir and Joe Simonetti