Rocket fire from Lebanon hit northern Israel on Wednesday prompting retaliatory shelling, the army said, as tensions rise between Israel and arch foe Iran.  "Three rockets were fired from Lebanon into Israeli territory," the army said in a statement, adding that one had fallen short of the border.

"In response... artillery forces fired into Lebanese territory."

The rockets hit near the northern town of Kiryat Shmona, where air raid sirens sent residents into bomb shelters.

Magen David Adom medics distributed images of a brush fire and said they treated four people suffering "stress symptoms". 

The army said it had imposed no restrictions on civilians in northern areas.

Asaf Langleben, head of civilian security for the northern Galilee region, told army radio that the rockets hit in peak tourism season.

"This was a surprise to us, but not something we didn't think could happen," he said.

Prime Minister Naftali Bennett said he and Defence Minister Benny Gantz had been "briefed" on developments and were overseeing Israel's response.

The exchange of fire comes days after Israel and other states accused Iran of being behind an apparent drone attack on an Israeli-linked tanker off Oman, which killed two crew members, and hinted at possible retaliation.

Iran denied the allegation and warned it would "respond to any possible adventurism."

Lebanon's powerful Shiite militant group Hezbollah, an Iran ally that fought a devastating 2006 war with Israel and is designated as terrorist group by much of the West, carries out attacks on Israel from time to time.

There was no immediate indication who had fired Wednesday's rockets.

In July, two rockets were fired at northern Israel from Lebanon, prompting retaliatory shelling. Gantz said the government would "not allow the social, political and economic crisis in Lebanon to turn into a security threat to Israel." 

In a tour of the military's northern command on Tuesday, Bennett said: "Iran already knows the price that we exact when someone threatens our security.

"Against Iran, speeches are not enough –- we need a strong (army) and for that we need to invest considerable resources, which we are doing," he said in remarks relayed by his office.