Russia and Ukraine swapped accusations of breaking a U.S.-brokered ceasefire on Sunday, with both sides claiming to have suffered casualties in drone and artillery strikes over the past 24 hours.

The United Arab Emirates said Sunday it intercepted two Iranian drones in its airspace in the latest test of a shaky ceasefire.

Recent days have seen the biggest flare-ups in fighting in and around the Strait of Hormuz ‌since a ceasefire began a month ago, and the United Arab Emirates came under renewed attack on Friday.

The shaky ceasefire in the Iran war was tested again on Sunday when a drone set a small fire on a ship off the coast of Qatar, while the United Arab Emirates and Kuwait reported separate drones entering their airspaces.

Oil rises in early Asian trade amid signs of ongoing Middle East tensions that could sustain supply disruptions.

The U.S. military said Friday that its forces had disabled two Iranian tankers that were trying to breach an American blockade of Iran’s ports.