BEIRUT — Hassan Nasrallah, the leader of Hezbollah, urged the Lebanese government on Thursday to take a more active role in finding a political solution to the civil war in neighboring Syria and to open its border to refugees to avert further bloodshed.

Nasrallah, the head of the Shi’ite militant movement in Lebanon, was addressing a ceremony in the town of Baalbek, near the Syrian border, by video link in observance of Arbaeen, the end of a 40-day mourning period for the death of Imam Hussein, a grandson of the Prophet Mohammed.