(AFP) - Israeli Prime Minister Benjamin Netanyahu on Monday warned Iran not to threaten Israel after Tehran launched ballistic missiles at a Syrian base of the Islamic State group.

Iran's Revolutionary Guard said it had fired six missiles from western Iran into northeastern Syria on Sunday, targeting "terror bases."

The Guard said the strike was "in retaliation" for June 7 attacks in Tehran that killed 17 people in the first IS-claimed operations in the country.

Netanyahu has repeatedly said Iran is a threat to the Jewish state, the Middle East and potentially the world.

"We follow their actions and we follow their words," he said Monday. "I have one message to Iran: Do not threaten Israel."

"The army and our security forces are constantly monitoring the activity of Iran in the region," Netanyahu told senior members of his Likud party on Monday.

"This activity also includes their attempts to establish themselves in Syria and, of course, to transfer advanced weapons to Hezbollah and other operations," a party statement quoted him as saying.

Netanyahu was a vocal opponent of the 2015 deal between Tehran and major powers that saw sanctions against Iran eased in return for curbs on its nuclear programme.

Israel, which is itself believed to have atomic weapons, says the programme aims to produce a nuclear bomb -- something Iran denies.

Iran's homemade missiles, including some that are capable of hitting Israel or American military bases in the region, are a major point of tension with Washington and Israel.

Defence Minister Avigdor Lieberman said Israel was not worried by Sunday's strike.

"Israel is prepared for every development," he told members of his right wing Yisrael Beitenu party on Monday.

"We are prepared, we have no concerns or worries."