The Israel Defense Forces activated its Iron Dome missile defense system Thursday after a false alarm caused rocket sirens to sound in several communities in the Golan Heights in northern Israel.

Residents in the area reported hearing an explosion. The IDF's Spokesman said an investigation is underway.

Last week, Israel attacked dozens of Iranian targets in Syria in what the military said was the most extensive strike in the neighboring country in decades. The strike was carried out in response to a barrage of 20 rockets that were fired from Syria at Israeli military outposts.

The Israeli military accused the Iranian Revolutionary Guards' Al Quds force and its commander, Maj. Gen. Qassem Soleimani, of launching the attack at the Israeli Golan Heights. It was the first time Israel has directly accused Iran of firing toward Israeli territory.

Reuters contributed to this report.