MARIB, Yemen — The missile attack launched by the Iran-backed Houthi militia killing 21 civilians, including a five-year-old girl, in Yemen's Marib has strongly been condemned. The ballistic missile that targeted the city's airport hit a gas station in the Rawdha neighborhood in Yemeni city Marib on Saturday. The diplomatic missions of the United States and the United Kingdom in Yemen denounced the "inhuman" Houthi attack. Denouncing the Houthi attack against civilians, Cathy Westley, charge d'affaires at the US embassy in Yemen, tweeted on Sunday, saying: "We are horrified by reports the Houthis used a ballistic missile to destroy a gas station in Marib, killing and wounding civilians". "The Houthis reportedly then used a drone to attack an ambulance crew coming to aid the injured. This inhuman violence must end". British Ambassador to Yemen Michael Aron, in a tweet on his official Twitter account, described the incident as shocking, saying: " Shocking reports of explosions at a petrol station in Marib leaving dozens of civilians killed & injured." "The Houthis must stop their Marib offensive and engage seriously with the UN," he added. The UK envoy also said in his tweet that the agreement on a nationwide ceasefire would prevent such tragic losses and allow humanitarian action. Meanwhile, Bahrain and Egypt also strongly condemned the 'immoral" Houthi attack. In a statement on Monday, Bahrain's foreign ministry said the attack is in flagrant violation of international humanitarian law and all moral values and principles. The Bahraini ministry expressed its deepest condolences and sympathies to the families of the victims, the Yemeni government, and people, and wished those injured a speedy recovery. It also affirmed Bahrain's solid solidarity with Yemen to stop the systematic and recurring Houthi crimes and stressed full support for the Yemeni efforts to preserve its security, stability, and the safety of its territories, citizens, and residents. It also called upon the international community to condemn the heinous attacks of the terrorist Houthi militia. On Sunday, the Egyptian foreign ministry stated that Egypt denounced "in the strongest terms" the new lethal missile assault conducted by the Houthi militia in Yemen's Marib. "Egypt also affirmed its support for the Yemeni government, reiterating its call for ceasing these reprehensible attacks, while seeking to uphold the interests of Yemen and its people," the foreign ministry added in its statement. The Arab Parliament also condemned the bloody massacre committed by the Houthi militia. In a statement, on Sunday, it said that these terrorist crimes represent war crimes and crimes against humanity, and require an urgent international trial for their perpetrators. "This represents a grave violation and disregard for all humanitarian norms and principles and international laws, especially international humanitarian law, which guarantees the protection of civilians, the statement read. The Arab Parliament called on the international community to intervene urgently and take decisive positions to stop these terrorist crimes committed by the Houthi coup militia. "These crimes reflect its persistence in undermining all regional and international efforts to resolve the crisis politically, and its blatant defiance of the international community," the statement added.