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Reuters
Israel's military says Iranian forces have fired rockets at its positions in the occupied Golan Heights
It said around 20 rockets were fired by Iran's Revolutionary Guard early on Thursday and some were intercepted, adding that there were no casualties.
Earlier this week, Israel said it had noted "irregular activity" by Iranian forces in the region.
It placed its troops in the Golan Heights on high alert and urged civilians to take shelter.
In a statement, the Israel Defense Forces (IDF) said it viewed the incident "with great severity and remains prepared for a wide variety of scenarios".
A spokesman for the military, Jonathan Conricus, said that Israel had retaliated for the attack but did not give details.
Syria's state news agency Sana later said Israeli missiles had been shot down over Syria by anti-aircraft defences.
The latest confrontation follows a reported Israeli missile strike on a military outpost south of the Syrian capital of Damascus on Tuesday.
Sana reported that two missiles were shot down in the Kiswah area and that two civilians were killed in an explosion.
But the Syrian Observatory for Human Rights, a UK-based monitoring group, said the missiles hit an Iranian weapons depot, killing 15 pro-government fighters.
Eight members of Iran's powerful Revolutionary Guards force and several other non-Syrian nationals were among those killed, it said.
Israel did not comment on the reports, but its government has vowed to stop what it considers Iran's military "entrenchment" in Syria.
Iran is a Syrian ally and has deployed hundreds of troops to the country.
Thousands of militiamen armed, trained and financed by Iran - mostly from Lebanon's Hezbollah movement, but also Iraq, Afghanistan and Yemen - have also been fighting alongside the Syrian army.