Syrian authorities insisted Wednesday they would "never be a threat" to anyone in the region, after Israel bombed the country's south in retaliation for overnight rocket fire on the Golan Heights.

Israeli media said the projectiles were the first launched from Syria into Israeli territory since the fall of longtime ruler Bashar al-Assad in December, with two unknown groups claiming responsibility.

The Israeli military said "two projectiles were identified crossing from Syria into Israeli territory, and fell in open areas". It later said it struck "weapons" belonging to the Syrian government in retaliation.

Defence Minister Israel Katz held Syria's leader "directly responsible".

Syria condemned the Israeli shelling as a "blatant violation of Syrian sovereignty" that "aggravates tensions in the region".

"Syria has never been and will never be a threat to anyone in the region," the foreign ministry said, in a statement carried by the official SANA news agency.

The ministry denied responsibility and said it could not confirm whether rockets were launched towards Israel, blaming "numerous parties... trying to destabilise the region".

There were no reports of casualties or damage on the Israeli side from the projectiles, which the military said triggered air raid sirens in the southern Golan Heights, a territory Israel seized from Syria in 1967 and annexed in 1981.

Katz said in a statement that "we view the president of Syria as directly responsible for any threat or fire directed at the State of Israel".

Syria's interim President Ahmed al-Sharaa led the Islamist group that spearheaded the offensive that toppled Assad.

Following Assad's overthrow, Israel moved its forces into the UN-patrolled demilitarised zone in the Golan, and has carried out hundreds of strikes against military targets in Syria.

Israel says the strikes aim to stop advanced weapons from reaching Syria's new authorities, whom it considers jihadists.

A group called the "Martyr Mohammed al-Deif Brigades", named after the Hamas commander killed by Israel in the Gaza Strip, released a video it said showed the moment the rockets landed in the occupied Golan Heights.

A second group known as the "Islamic Resistance Front in Syria" claimed responsibility for launching the two rockets at Israel. The group was created a few months ago and called for action against Israel from south Syria.

AFP was unable to verify the authenticity of their claims.

SANA reported Israeli shelling "targeting the Yarmuk Basin, in the west of Daraa" province.

The Syrian Observatory for Human Rights said bombardments had hit farmland in the province, without reporting casualties.

"Violent explosions shook southern Syria, notably the town of Quneitra and the Daraa region, following Israeli aerial strikes" overnight, the Britain-based war monitor said.

Since taking over, Sharaa has said Syria does not want conflict with its neighbours, urging international pressure on Israel to halt its attacks.

Analyst Bassam al-Suleiman said those benefiting from the escalation were "Iran and its militias", former Assad allies with a past presence in Syria.

A strong government in Damascus "apparently contradicts the Israeli vision for Syria" as a weak neighbour, he said.

Israel's recurring bombings of Syrian army infrastructure "hinders the emergence of a force capable of controlling all of Syria", Suleiman added.

Syria and Israel have technically been at war since 1948.

US President Donald Trump last month lifted sanctions on Syria and expressed hope for eventual normalisation with Israel though analysts say that remains unlikely.

During a visit to Damascus last week, US Special Envoy for Syria Thomas Barrack proposed a "non-aggression agreement" as a starting point between the two countries.