Two Katyusha rockets fell near Baghdad airport on Sunday but caused no casualties, the Iraqi military said. It was the third such attack on sensitive sites in the capital this week. On Saturday, a rocket fell inside Baghdad's heavily fortified Green Zone, which houses government buildings and foreign missions, while three others landed there on Thursday. Those attacks also caused no casualties. Washington blames such attacks on Iranian-backed militias. Iran has not directly commented on the incidents. Iraq, often the scene of violence from US-Iran tension, seeks to avoid being drawn into any regional conflagration. The Middle East came close to a large conflict in January after a US drone strike killed Iranian general Qassem Suleimani and Iraqi militia chief Abu Mahdi Al Muhandis at Baghdad airport. Iran-aligned militias have sworn to avenge their deaths.