New Delhi, April 19 -- Iran's Revolutionary Guard fired at two Indian-flagged merchant vessels in the Strait of Hormuz on Saturday, prompting the external affairs ministry to call in the Iranian envoy to lodge a formal protest over the incident. This was the first instance of Iran's Islamic Revolutionary Guard Corps (IRGC) firing at Indian-flagged or owned merchant shipping in the crucial waterway, which is used to transport 50% of India's oil imports. In recent weeks, at least nine Indian-flagged vessels have safely transited the strait. The shipping ministry in a status update said that an oil tanker, the MT Desh Garima, transited the strait at 1pm IST and is bound for Mumbai. Thirteen India-flagged ships remain in the Persian Gulf, west ...