Media outlets have reported that missiles launched by Israel, in an apparent retaliation for Iran's airstrike on Israel last weekend, have struck targets within Iran.

According to ABC News, which cited a senior U.S. government official, Israel launched missiles in a retaliatory strike against Iran early Friday, local time.

Iran's semi-official Fars News Agency said three explosions were heard near a military base where fighter jets are located in the Isfahan province, although the cause of the blasts remains unknown. According to the agency, it said that a military radar was one of the possible targets.

Reuters said the region, south of the capital Tehran, is the location of multiple nuclear facilities, while CNN reported that the area where explosions were heard is near the eighth hunting base of the Air Force. Citing a U.S. official, CNN said Israel will not likely target Iran's nuclear facilities.

Citing an Iranian government official, Reuters said Iran’s air defense system was activated in response to the attack, with Iranian outlets reporting that drones, not missiles, were used in the attack from Israel.

The Associated Press reported an airstrike was conducted on southern Syria, but ABC News, citing a U.S. official, said attacks outside Iran cannot be verified.