The Gulf Cooperation Council has criticised Lebanon's Hezbollah chief Hassan Nasrallah for threatening to send more fighters to neighbouring Syria after a car bomb hit his Shia party's stronghold.
"At the same time that he calls for self restraint, he threatens the Syrians that his party will be more involved in fighting them," GCC secretary general Abdullatif al-Zayani said in a statement released late Monday.
"This is a flagrant meddling in their (Syrians') internal affairs and an obvious violation of the Syrian sovereignty," he said, describing Nasrallah's speech of being "irresponsible".
"Nasrallah continues to boast about the participation of his militia in slaughtering children, women and innocent Syrians, and destroying their towns and property," Zayani said.
He even boasts that he is "ready to double the number of his militia fighters and even to join the fight himself against the Syrian people," Zayani added.
The head of the Iran-backed movement accused radical Sunni Islamists, who have joined the fight against the Syrian regime, of being behind last week's car bomb in the predominantly Shia southern suburb of Beirut, which killed 27 people and wounded 336.
"I will go myself to Syria if it is so necessary in the battle against the takfiris (radical Sunni Muslims); Hezbollah and I will go to Syria" to fight rebels trying to oust President Bashar al-Assad, said Nasrallah defiantly.
Hezbollah is a key supporter of Syrian President Bashar al-Assad and has sent fighters across the border this year to bolster government forces, which have been battling an anti-regime revolt since March 2011.
Oil-rich GCC countries, which are backing the uprising, have imposed sanction on Hezbollah over its support for Assad.
The GCC comprises Bahrain, Kuwait, Oman, Qatar, Saudi Arabia and the United Arab Emirates.