UNITED NATIONS - The United Nations is concerned about Iran's missile attacks against what Tehran called the bases of terrorists and Israel's intelligence service Mossad in Syria and Iraq, said a UN spokesman on Tuesday.

"We are very concerned about these reported ballistic strikes that have been claimed by the Islamic Revolutionary Guard (Corps) that hit ... targets in Syria (and) in Iraq as well," said Stephane Dujarric, spokesman for UN Secretary-General Antonio Guterres.

"We once again urge maximum restraint and avoid any further escalation in a region that ... is already volatile and increasingly so. This kind of situation also can lead to miscalculation by parties with even worse consequences," he said.

Dujarric said the secretary-general further underlines that all security concerns between Iraq and Iran must be addressed through peaceful means and dialogue, in accordance with the principles of sovereignty, territorial integrity, and good neighborly relations.

Iran's Islamic Revolutionary Guard Corps said Tuesday that it has launched barrages of ballistic missiles against the bases of "terrorists" and Israel's intelligence service Mossad in Syria and Iraq's Kurdistan Region in response to recent anti-Iran "terror" attacks.