The Hezbollah militant group says at least three of its fighters were killed in Israeli strikes on Wednesday as a U.S. envoy works to quell tensions.

Lebanese state media reported multiple Israeli strikes along the border and in an area north of the coastal city of Tyre, about 30 kilometers (20 miles) from the frontier. The Israeli military said two Hezbollah launches damaged several vehicles in northern Israel.

The fighting came as Amos Hochstein, a senior adviser to U.S. President Joe Biden, returned to Israel after meeting with officials in Lebanon on Tuesday. There has been no word on whether he has made progress in his efforts to avoid a devastating regional war.

Kamel Mohanna, the head of the Amel Association, an NGO providing health services in Lebanon, said the group’s primary health center in the town of Khiam was hit and damaged by Israeli shelling. Mohanna said he was visiting another health center in south Lebanon, which had been previously struck and then repaired, when the Khiam center was hit.

Israeli strikes already have killed more than 400 people in Lebanon, most of them Hezbollah fighters, but at least 80 of the fatalities were civilians. In northern Israel, 16 soldiers and 11 civilians have been killed.