A Syrian regime warplane crashed in the northern countryside of Aleppo on Thursday, Russia’s Sputnik news agency reported. “During a routine training, a jet of the Syrian Arab Air Force crashed near the Kuweires Military Aviation Institute, the main training facility of the air force, as a result of a technical failure,” it said. The agency added that the pilot was killed in the crash, denying that the jet was attacked. Meanwhile, the Kurdish-led Syrian Democratic Forces (SDF) said Thursday they has launched an offensive against ISIS fighters, days after extremist gunmen launched a deadly prison attack. Six Kurdish fighters were killed Monday when ISIS militants attacked a complex in Raqqa, the extremist group’s former de facto capital in Syria, in a bid to free fellow militants imprisoned there. The SDF said the operation was being carried out alongside the US-backed coalition. Early this week, Kurdish-led authorities announced a state of emergency in Raqqa and put the city on lockdown as security forces hunted down extremists, AFP reported. Raqqa was an ISIS stronghold until 2017. The SDF assumed control of the city after the extremist group’s defeat in Syria. On Thursday, the SDF launched “Operation al-Jazeera Thunderbolt,” aimed to “eliminate” ISIS gunmen from areas that had been “the source of the recent terrorist attacks.”