Syrian rebels on Tuesday threatened to carry out attacks against Hezbollah inside Lebanon, a dangerous escalation of the conflict that could destabilize Syria's politically volatile neighbor as well as the region.
The heightened tensions on both sides of the border came as four mortar rounds hit one of Syrian President Bashar Assad's palaces in Damascus the same day, opposition activists said.
The presidential media office issued a statement saying that the mortar rounds had landed near the palace, not inside the palace grounds, without causing serious damage.
There was no statement from either side as to whether Assad was in the palace at the time.
In another sign of the heavy toll that the conflict has taken on civilians, the World Health Organization announced Tuesday that about 2,500 people have been infected with typhoid in northeastern Syria because of unsanitary conditions.
Tuesday's threat to bring the fight to Lebanon, issued by the Free Syrian Army, came after several days of clashes between Syrian rebels and militants from Hezbollah around Qusayr, a Syrian town near the Lebanese border, and a handful of smaller villages in the area, according to the rebels.