Army defectors in Syria are claiming responsibility for a rocket-grenade attack on a building belonging to the ruling party in Damascus.
It was claimed by the Free Syrian Army, a group of military defectors.
If confirmed, it would be the first such attack reported inside the capital since an uprising against President Bashar al-Assad began in March.
Four government intelligence agents were killed on Saturday. The BBC reports their car was ambushed in Hama by gunmen believed to be army defectors.
Foreign journalists are unable to move around Syria freely, making it difficult to verify reports.
Government supporters took to the streets of Damascus again on Sunday, carrying a giant portrait of Mr Assad.
The Arab League has rejected counter proposals put forward by Damascus to a proposal to send a delegation to Syria.
A statement on the League's website says the amendments would radically alter the delegation's mission, adding the proposal was not up for negotiation with Damascus.
Arab League foreign ministers are to meet again on Thursday. Syria's membership was suspended last Wednesday after it failed to honour the terms of a peace plan put forward by the league.