The leader of Lebanon's Hezbollah has accused Saudi Arabia of being behind last month's two suicide bombings that targeted the Iranian Embassy in Beirut.
Sheikh Hassan Nasrallah's comments on Tuesday mark the first time Hezbollah has openly accused the kingdom, and marks a sharp escalation in the Shia Muslim group's rhetoric.
An al-Qaeda linked group has claimed responsibility for the November 19 attack that killed 23 people, saying it was in response to Hezbollah and Iran's involvement in Syria.
Nasrallah said the claim was credible but accused Saudi intelligence of providing backing and support.
He also said Saudi intelligence was behind daily attacks in Iraq.
Nasrallah spoke in an interview Tuesday with Lebanon's private OTV network.
Elsewhere in Lebanon, clashes resumed on Tuesday between Lebanese armed groups who back opposing sides of Syria's war and 21 fighters were arrested by the army as it pursued a six-month-long mandate to end bloodshed battering the city of Tripoli.
The conflict between the majority Sunni Muslim Bab al-Tabbaneh district and the adjacent Alawite neighbourhood of Jebel Mohsen in Tripoli has killed more than 100 people this year.
But residents, fighters and a local politician told Reuters on Tuesday it was unlikely to end soon despite army efforts.
Over the weekend, the relatives of the car bomb victims protested in a Tripoli square, demanding that leading Alawite political leaders be arrested and calling for Jebel Mohsen's electricity and water supplies to be cut off.
The latest clashes started after repeated attacks on Alawite targets over the past week in which several people were wounded.
Ten people were killed over the weekend.
The army provided no details on the 21 men seized by soldiers.