Iran said on Friday it had successfully conducted an air defense exercise using drones designed to intercept “enemy targets” in an area along its southern coast, amid escalating tensions in the region, Reuters reported.

The announcement came after Pakistan carried out airstrikes on Thursday against targets in Iran that it said were targeting separatist militants.

President of Pakistan Arif Alvi said that his country fully respects the sovereignty and territorial integrity of all states, expecting the same attitude from other countries.

“Pakistan will not compromise on national security and territorial integrity and will take all necessary measures to protect its territory,” Alvi said, according to a statement released by his office on social media.

The retaliatory strikes came two days after the Revolutionary Guards, an elite unit of Iran’s armed forces, launched coordinated airstrikes on targets in Syria, Iraq and Pakistan in response to a January 3 terror attack in Kerman claimed by Islamic State.

The mutual strikes represent the sharpest escalation of tensions in the Middle East in recent years, raising serious concerns about growing instability in the region.

“Iranian forces have successfully launched a new air defense method that uses drones to intercept and target enemy targets,” local media quoted an Iranian military official as saying on Friday.

The exercise, which began on Thursday, covered an area stretching from Iran’s southwestern Khuzestan province to Sistan and Baluchistan in the country’s southeast, regions bordering Pakistan and Afghanistan.

Local television reported that the Air Force, Navy, and Revolutionary Guards took part in the exercise.

Iran and Pakistan have a history of tumultuous relations, but Reuters notes that both countries have used diplomatic channels to signal that they want to ease tensions fueled by strikes on each other in recent days.