U.S. strikes on Iran's nuclear sites could heighten the threat to American operators in the region, an organisation that monitors flight risks warned on Sunday, as some airlines cancelled flights to and from Dubai and Doha.

Airlines continued to avoid large parts of the Middle East due to ongoing missile exchanges between Israel and Iran, the latest upheaval to travel in the region. Singapore Airlines said it cancelled scheduled flights from Singapore to Dubai following a security assessment and British Airways cancelled flights to and from Dubai and Doha.

United and American Airlines have suspended flights to the Middle East due to escalating conflict between Iran and Israel.