Syrian state media said Thursday the United Kingdom's decision to join U.S.-led airstrikes in the region violates international law. Comments from Syrian newspapers came after the British Parliament approved a motion Wednesday to join airstrikes targeting the Islamic State terror group, also known as ISIS or Daesh, in Syria, and the first airstrikes began Thursday.

Four British RAF Tornado jets took off from Cyprus Thursday, carrying out air missions against the Omar oil fields in ISIS-held territory in eastern Syria, the BBC reported. British Defense Secretary Michael Fallon personally selected the targets and described the mission as "successful."

One government-run Syrian newspaper, Al-Thawra, accused the British Parliament of “vaulting over international legitimacy as usual," the Independent reported. Syrian authorities said the British government should have asked permission from the Syrian regime to join airstrikes. The U.K. already participates in strikes on ISIS in Iraq, and the motion passed Wednesday extended military action into Syria.

The U.S. and its allies, including France and Turkey among others, have been conducting airstrikes against ISIS targets in Syria since 2014, hitting several thousand targets. The strikes have been used to destroy ISIS bases and sources of funding such as oil fields, as well as to target specific individuals.

France in particular issued calls for heightened airstrikes and increased international support in Syria following a series of deadly terror attacks in Paris that left 130 dead Nov. 13. ISIS claimed responsibility for those attacks and several of the terrorists involved trained in Syria.

Citizens and media from around the world have criticized the strikes because of the high number of civilian casualties. The debate in the British Parliament Wednesday highlighted the division between those who said airstrikes were the only way to protect Europe from Islamic terrorism and those who said destroying Syrian targets would fuel more extremism.