Israel killed a Hezbollah fighter in a strike on Syria, close to the Lebanese border, also hitting near Damascus Thursday, a war monitor said, hours after similar attacks.

Hezbollah holds sway over Lebanon’s eastern border with Syria, as well as some regions on the other side of the border including Qusayr, the target of Thursday’s strike.

“An Israeli drone strike on a truck killed a Hezbollah fighter in the Qusayr area near the Syrian-Lebanese border,” said Rami Abdel Rahman, who heads the Syrian Observatory for Human Rights.

At the same time, Israeli strikes targeted Syrian air defense and radar sites near Damascus, said the Britain-based monitor with a network of sources inside Syria.

An AFP correspondent in Damascus heard faraway explosions.

Syrian state media did not report the strikes.

Hezbollah and other Iran-backed groups have been fighting alongside Syrian President Bashar Assad’s forces following the eruption of civil war.

Since Syria’s war began in 2011, Israel has launched hundreds of air strikes against its northern neighbor, primarily targeting pro-Iran forces, among them Lebanon’s Hezbollah and the Syrian army.

But the strikes have multiplied during the almost five-month-old war between Israel and the Palestinian militant group Hamas.

On Wednesday evening, Israel struck near Damascus, killing two Syrian pro-Hezbollah fighters, the Observatory had said.

Last week, an Israeli strike on a truck in Syria near the Lebanese border killed two Hezbollah members, also according to the Observatory.

Israel rarely comments on individual strikes but has repeatedly said it will not allow Iran to expand its presence in Syria.

Syria’s war has claimed the lives of more than half a million people and displaced millions since it broke out in March 2011 with Damascus’s brutal repression of anti-government protests.