Dubai: The United States expanded its airstrike campaign against Iran early Friday by increasingly hitting bridges, part of President Donald Trump's threats to start striking infrastructure to pressure Tehran to ease its chokehold on the Strait of Hormuz. Iran launched new missile attacks against U.S.-allied nations in the Middle East and warned that its attacks would escalate.The interim ceasefire agreed to last month has collapsed, and the region has endured days of back-and-forth attacks by the U.S. and Iran as they battle for control of the strait. Iranian officials say U.S. strikes have killed more than 35 people and wounded over 300 others, with new casualties reported in Friday's strikes.Also read: Trump threatens new Iran escalation and risks repeating old mistakesWhen the U.S. and Israel launched the war on Iran on Feb. 28, Tehran effectively closed the strait to shipping traffic, a move that sent the price of oil soaring and gave Iran major leverage in negotiations.Col. Ebrahim Zolfaghari, a spokesperson for the Iranian military's Khatam al-Anbiya Central Headquarters, earlier threatened that Iran could launch widespread attacks on "all the infrastructure in the region" if the U.S. acted on Trump 's repeated warnings that America could hit Iranian bridges and power plants."Under no circumstances and in no way will we allow America, as a foreign and extraregional country, to interfere in the Strait of Hormuz," he added. "This is Iran's invincible red line."