At least 50 cruise missiles have been launched from ships in the Eastern Mediterranean into Syria, multiple media outlets report.

The missile salvo comes in response to the use of chemical weapons to kill more than 100 civilians in Ash Sha’irat in Homs province in western Syria, apparently by the Syrian government.

American officials told NBC News that the missiles targeted and struck airfields and runways, not people. There is no word yet on casualties.

Secretary of State Rex Tillerson said Thursday that “there is no doubt in our minds” that the Syrian regime was responsible for the chemical attack. American Ambassador to the United Nations Nikky Haley told the UN Security Council, “When the United Nations consistently fails in its duty to act collectively, there are times in the life of states that we are compelled to take our own action.”

Tillerson and Haley also warned Russia to reconsider its support of the regime of Syrian president Bashar al Assad.