Egypt launched airstrikes against ISIS-controlled territories in Libya on Monday, just hours after the Islamist group posted video of 21 kidnapped Egyptian Christians apparently being beheaded.

"Avenging Egyptian blood and punishing criminals and murderers is our right and duty," the Egyptian military said in a statement broadcast on state television, according to CNN. The executed Egyptians were reportedly kidnapped in December and January from the Libya city of Sirte, where the men had traveled for work.

The Egyptian airstrikes targeted ISIS training camps and weapons depots in the eastern city of Derna, according to the New York Times, though it wasn't clear if there were any casualties or how much damage was done.

[Image via AP]