The explosions that killed more than 100 people in Iran on Wednesday took place at an anniversary commemoration for Maj. Gen. Qassim Suleimani, the top Iranian commander who was killed by a U.S. drone strike four years ago. General Suleimani, the most powerful Iranian commander at the head of the foreign-facing arm of Iran's Revolutionary Guards Corps, was considered a hero by some in Iran and in other parts of the region for building an axis of allied militias to defend Iran's interests across the Middle East, to counter the United States and Israel, and for helping to defeat the Islamic State in Syria and Iraq. In the United States, he was regarded as a force behind international terrorism campaigns, and President Donald Trump said his killing in January 2020 was ordered "to stop a war" because General Suleimani had been plotting attacks on American diplomats and military personnel. General Suleimani was designated as a terrorist by the United States and Israel, where he helped orchestrate waves of militia attacks.

Get live updates and reaction here. The American drone attack near the Baghdad airport early Friday that killed Maj. Gen. Qassim Suleimani, the powerful Iranian commander, drastically ratcheted up tensions between Washington and Tehran, threatening to tip hostilities into war. Here's what to know about what happened and what comes next. General Suleimani was Iran's most powerful security and intelligence commander.