United States President Donald Trump said on Tuesday, June 24, that a ceasefire between Israel and Iran was now in place and asked both sides not to violate it, raising hopes of an end to the 12-day war that has threatened regional security in the Middle East. The conflict has raised fear of more instability in the region, with a number of countries, including Qatar, closing their airspace, leading to flight disruptions. RwandAir, for example, announced on Monday that it had cancelled flights to and from Doha and Dubai, two of the busiest destinations in the Middle East. ALSO READ: RwandAir cancels flights to Doha, Dubai Israeli Prime Minister Benjamin Netanyahu said Israel had agreed to Trump's ceasefire proposal, declaring that his country had achieved its goal of removing Iran's nuclear and ballistic missile threat, but warning that it would respond forcefully to any violations, his office said. Writing on Truth Social earlier, Trump declared: THE CEASEFIRE IS NOW IN EFFECT. PLEASE DO NOT VIOLATE IT! His announcement came after Iran had launched a fresh wave of missiles, killing four people, according to Israel's ambulance service, and as Iranian authorities reported nine people killed in an attack in northern Iran on Tuesday morning. ALSO READ: Qatar closes airspace amid fears of regional conflict When Trump announced on Monday what he called a complete ceasefire to end the war, he appeared to suggest that Israel and Iran would have time to complete missions that were underway, at which point the ceasefire would begin in a staged process. His declaration came after a sharp escalation of the conflict since Saturday, when the United States bombed Iranian nuclear sites, prompting Iran to retaliate by firing missiles at a U.S. base in Qatar on Monday. A senior White House official said Trump had brokered the ceasefire deal in a call with Netanyahu and Israel had agreed so long as Iran did not launch further attacks. On the assumption that everything works as it should, which it will, I would like to congratulate both Countries, Israel and Iran, on having the Stamina, Courage, and Intelligence to end, what should be called, 'THE 12 DAY WAR', Trump wrote on his Truth Social site.