Hyderabad, April 20 -- Iran's foreign minister, Hossein Amirabdollahian, warned on Friday that Iran would respond immediately and at the maximum level if Israel retaliated and acted against the interests of Iran.

The statement came after an overnight attack on Iran, which Iranian officials described as an attack by "infiltrators" rather than by Israel, reported Reuters.

The incident involved a small number of explosions, which resulted from air defenses hitting three drones over Isfahan in central Iran in the early hours of Friday.

Amirabdollahian told NBC News that the drones took off from inside Iran and flew for a few hundred meters before being downed. He added that Iran was investigating the matter but that media reports were not ...