A heavy dust storm roared into Iran’s capital on Monday, blacking out the sun in a swirling cloud and tearing down trees in a squall that reportedly killed at least four people and injured 30. The storm struck Tehran with winds of up to 68 miles per hour, state television reported. The television report said the storm killed five people. Iran’s official IRNA news agency said it killed four people as winds hit 80 miles per hour. The discrepancy could not immediately be reconciled. The storm broke trees and plunged the capital into darkness for several minutes.