A small cargo ship was attacked on Tuesday by Yemen's Iran-aligned Houthis in the Bab el-Mandeb Strait, killing three crew members, said two Yemeni coast guard sources and two military officials in the government. Maritime security sources told Reuters a small cargo ship was believed to have been targeted in the Red Sea, but the fate of the crew was unclear. If confirmed, the fatalities on the Tanzania-flagged Tihamah would be the first deaths in a Houthi strike on a ship since Middle East conflict was triggered by US-Israeli attacks on Iran at the end of February. The Houthis have not yet claimed the attack, which Yemeni sources said killed two Pakistanis and one Indonesian person on the boat sailing from Salalah in Oman via Djibouti. Attacks on ships in the Bab el-Mandeb Strait have increased uncertainty for shipping companies already hobbled by the closure of the Strait of Hormuz. An average of 32 ships per day passed through the Bab el-Mandeb strait last week, Kpler data showed. Prior to the blockade an average of 50 ships per day transited the strait. The Houthis also attacked the government-held port city of Mokha on the Red Sea coast and other areas of the country, deepening fears over threats to strategic shipping routes and a potential return to civil war. Yemen's military said the militants targeted both Mokha and the central province of Marib with missiles and drones. The Houthis struck Marib and the eastern province of Hadramawt last week, killing dozens of government troops and civilians. They hit Mokha with missiles and drones over the weekend and killed at least seven people, including three troops, according to the Yemeni military.