The Israeli strikes came a day after Syrian president Bashar al-Assad was ousted from power and were among more than 300 raids across Syria in recent days, according to the Syrian Observatory for Human Rights.

The Observatory reported that overnight Monday, "Israeli warplanes" had damaged about 10 navy ships and hit additional military targets, including "the Barzeh scientific research centre" and army warehouses in and around Latakia's port.

Israeli Defence Minister Israel Katz said the navy struck Latakia with missile ships.

Western countries, including the United States, struck the Latakia research facility in 2018, saying it was related to Syria's "chemical weapons infrastructure".

On Tuesday morning, an AFP journalist at the scene described the three blocks of buildings that made up the centre as destroyed, with hundreds of documents scattered around, fires still burning at the facility and the strong smell of explosives lingering in the air.

At the port, a plume of dark grey smoke rose above at least three Soviet-era warships equipped with machine guns and missile launchers that had been part of the Syrian navy.

A port worker described hearing "strange and unusual sounds" through the night, and said he later found out about the strikes from his colleagues and social media networks.

"We asked around about what was happening, no one knew. There was no electricity, but we found out through Facebook that these were Israeli air strikes targeting the port," Samir Alloush said.

Another worker, Ahmed Khabbazi, also said he "heard the sounds of the air strikes".

"This morning, we went down and saw that the Israeli army had struck the former regime's military boats," he said.

- Netanyahu warns new rulers -

The region of Latakia is the heartland of Assad's minority Alawite community, but after the rebel takeover, people toppled a statue of the deposed president's father.

Visiting one of Israel's key naval bases in Haifa on Tuesday, Katz confirmed the military had hit several Syrian naval vessels in overnight "extensive operational activities".

He said the operation had been carried by the Israeli navy using "missile ships."

"The navy operated last night to destroy the Syrian fleet with great success," Katz said in a statement.

He said the military "has been operating in Syria in recent days to strike and destroy strategic capabilities that threaten the State of Israel."

"I warn here the leaders of the rebels in Syria: anyone who follows Assad's path will end up like Assad -- we will not allow an extreme Islamic terrorist entity to act against Israel beyond its border, putting its citizens at risk."

Katz said that together with Prime Minister Benjamin Netanyahu, he had instructed the military to "establish a sterile defence zone free of weapons and terrorist threats in southern Syria, without a permanent Israeli presence."

Later on Tuesday, Netanyahu warned the new rulers in Syria against following in the footsteps of the previous regime and allowing Iran to "re-establish" itself in the country.

"If this regime allows Iran to re-establish itself in Syria, or permits the transfer of Iranian weapons or any other weapons to Hezbollah, or if it attacks us -- we will respond forcefully, and we will exact a heavy price", Netanyahu said in a video statement.

"What happened to the previous regime will happen to this one."