Tensions across northern Syria have escalated sharply amid a series of clashes between powers, including Israel, Iran, Turkey and the Syrian government. On Saturday, Israel shot down what it claims was an Iranian drone that had entered Israel’s airspace after being launched in Syria. Israel then mounted an attack on an Iranian command center in Syria, from where the drone was launched. One of the Israeli F-16 military jets was then downed by a Syrian government anti-aircraft missile. Israel then carried out a series of retaliatory strikes against both Syrian and Iranian targets in Syria.

Saturday’s events mark the first Israeli jet shot down since the 1980s. It is also believed to be the first time Israel has carried out an attack in Syria on a site where Iranian troops were present.

Meanwhile, also in northern Syria on Saturday, a Turkish Army helicopter was shot down by U.S.-backed Syrian Kurdish YPG fighters near the Syrian Kurdish city of Afrin, where Turkey has launched a bombing and ground offensive. All this comes as the United Nations is warning of soaring levels of civilian casualties in Syria. This is Elizabeth Throssell, spokesperson for the Office of the U.N. High Commissioner for Human Rights.

Elizabeth Throssell: “This has been a week of soaring violence and bloodshed in Syria—more than a thousand civilian casualties in six days. We’ve received reports that at least 277 civilians have been killed; 230 of these people were killed in airstrikes by the Syrian government and their allies. In addition, 812 people were injured.”