The Iranian Revolutionary Guards have fired medium-range missiles from western Iran into eastern Syria today, targeting an ISIS base in Deir Ezzor Province in the first Iranian missile launch in fighting since the end of the Iran-Iraq War, some 30 years ago.

While Iran has been fighting against ISIS in Syria for years, Iranian state media presented the launch of missiles as direct retaliation for ISIS terror attacks in the capital city of Tehran this month. They reported a large number of ISIS killed in the missile strikes, but exact figures are still unclear.

That Iran is publicly connecting these missile strikes to the Tehran attacks makes clear how seriously they view those attacks. Tehran has rarely been a target of foreign terror groups, but in the immediate wake of the attacks, targeting parliament and the mausoleum of Iran’s founder Ruhollah Khomeini, officials downplayed the seriousness of the situation.

This is likely to bring new attention to Iran’s development of conventional missiles, something that US officials have used as a justification for sanctions. That Iran’s only use of these missiles in the past several decades was against ISIS, and the previous use was in defending their country from an Iraqi invasion, reflects that Iran’s missile program has been very limited, and largely defensive in nature.