BEIRUT - The Syrian state news agency said a Saudi-led military operation launched in Yemen on Thursday was an act of "blatant aggression."
"Gulf war planes led by the regime of the Saudi family launch a blatant aggression on Yemen," read a headline carried on the website of the state news agency SANA.
The Syrian government led by President Bashar Assad is an ally of Iran, which is in turn allied with the Yemeni Houthi rebels who are fighting to oust the country's US-backed president. Saudi Arabia and other Gulf states have been important sponsors of the insurgency against Assad.
The Syrian crisis now in its fifth year has been another major theatre where Saudi-Iranian rivalry has played out in a regional conflict that has taken on a sectarian dimension pitching Sunni and Shi'ite Muslim against each other.
Shi'ite Islamist-led Iran has given military and financial backing to the Syrian government led by Assad, a member of the Shi'ite-linked Alawite sect.
The Iranian-backed Shi'ite Lebanese group Hezbollah has battled alongside the Syrian army against the Sunni-dominated insurgency, which has been sponsored by states including Sunni-led Saudi Arabia and is now dominated by jihadist groups.