"We are in Syria at the request of the Syrian government," said Alaeddin Boroujerdi, president of Iran's parliamentary foreign affairs committee.

"The aggression of the Zionist entity on our advisers in Syria guarantees us the right of response," said Boroujerdi.

"We will respond at the right time and place," he told a news conference in the Syrian capital Damascus.

Boroujerdi was speaking at the end of a two-day visit to Syria, during which he met President Bashar al-Assad.

On Monday, a monitor said missile strikes on central Syria killed 26 pro-regime fighters, most of them Iranians, in a raid it said bore the hallmarks of an Israeli operation.

Israeli Intelligence Minister Yisrael Katz told army radio that he was "not aware" of the strikes.

The latest such attacks came amid heightened tensions after Damascus and Tehran accused Israel on April 9 of conducting deadly strikes against a military base in central Syria.