One of Iraq's most powerful Iranian-backed Shi'ite militias on Sunday warned that Arab forces sent to Syria or Iraq would "open the gates of hell," in comments clearly aimed at Sunni Arab countries that have said they might join such an operation.
"The Arab kingdoms tried Daesh mercenaries to implement their malicious plans in Iraq and Syria, and they failed," a statement from Kataib Hezbollah said, using an Arabic acronym for Islamic State.
It called on "the sons of Saud and those rulers who stand behind them not to take a risk and to learn (their) lesson," referring to the Saudi ruling family.
Kataib Hezbollah, whose leader Abu Mahdi al-Mohandes heads the Baghdad-sanctioned coalition of mainly Shi'ite militias battling the ultra-hardline Sunni Muslim militants of Islamic State alongside Iraq's regular forces, has sent fighters to Syria to support President Bashar Assad's troops in that country's five-year-old civil war.
The United Arab Emirates (UAE) said on Sunday it was ready to supply ground troops to help support and train an international military coalition against Islamic State in Syria provided such efforts were led by the United States.
Saudi Arabia, one of several Sunni Gulf Arab states, including the UAE, who are opposed to Islamic State, said last week it was ready to participate in any ground operations in Syria if the US-led coalition fighting Islamic State militants decided to start such operations.
Syria's foreign minister warned on Saturday that Damascus would resist any ground incursion into its territory and send the aggressors home in coffins.