Sanaa, Feb 20 : Yemen's Houthi group launched an explosive-laden drone strike against a school in the country's northern oil-rich province of Marib, a government official said. "Several students were critically injured when a Houthi explosive-laden drone struck their school in the government-controlled province of Marib," the official told Xinhua news agency on Saturday. He clarified that the Houthi drone attack hit the primary school of Harib district while the students were leaving their classes. Meanwhile, Yemeni state-run Saba news agency reported that at least three students were injured as a result of the Houthi drone attack. In January, the pro-government Giants Brigades troops launched a large-scale military operation and expelled the Houthi militia out from the district of Harib following fierce battles. The Houthis are still launching sporadic military operations against Marib, in an attempt to control the whole strategic province that includes the country's largest oil and gas fields. Yemen has been mired in a civil war since the Houthi militia overran much of the country militarily and seized all northern provinces, including the capital Sanaa, in 2014. Saudi Arabia has been leading a military coalition that intervened in Yemen in 2015 to support the government of President Abd-Rabbu Mansour Hadi after the Houthis forced him into exile. /IANS