RIYADH — The Coalition to Support Legitimacy in Yemen announced on Sunday the start of a qualitative military operation with heavy airstrikes against the Houthi militia in Yemen. The military operation targets Houthi capabilities in the occupied capital Sanaa and a number of other Yemeni governorates. The operation comes after the interception and destruction of 12 explosive-laden drones, all of which attempted to target civilians and civilian objects in the Kingdom in a deliberate and systematic manner on Sunday. The Coalition stressed that civilians and civilian objects in Saudi Arabia are a red line, saying: "We will hold accountable terrorist leaders who try to target civilians and civilian objects. The launched qualitative operation is in accordance with international humanitarian law and its customary rules," the Coalition said in a statement. The Coalition said that the reality on the ground and the victories of the Yemeni army and the tribes in Marib explains the pace of terrorist escalation represented by the Houthi militia. Removing the Houthis from the list of terrorist groups (by the US) was interpreted in a hostile way by the militia, according to the Coalition statement. The Coalition had confirmed earlier that the Houthi militia had launched explosive-laden drones in an attempt to target civilians and civilian objects in a systematic and deliberate manner. "We take operational measures to protect civilians and civilian objects in accordance with international humanitarian law," the statement added.