An unidentified object crashed and caused an explosion about 90 kilometers (55 miles) into Poland early Thursday, local authorities said, as Russia launched deadly longe-range attacks overnight across Ukraine. An F-16 fighter jet was scrambled to intercept and identify it, but the object disappeared from radar about six minutes later. Polish Prime Minister Donald Tusk confirmed a violation of Polish airspace during the attack, though authorities have not yet determined whether the object was a Russian missile. Poland Probes Mysterious ExplosionPolish police said they received a report of a loud explosion early Thursday near Tarnawa-Kolonia, in Lublin province, about 75 kilometers from the Ukrainian border. Polish authorities said they are continuing to investigate the crash site and have not yet confirmed the origin of the object.