Pakistan said early Thursday that it had carried out airstrikes on 10 sites in Afghanistan that it said were used to launch drone attacks against Pakistan a day earlier, a sharp escalation in recent fighting between the neighbors that threatens mediation efforts. There was no immediate response from Kabul to the latest strikes, but a spokesperson for Afghanistan’s Taliban government denied Wednesday that Afghan Taliban forces had carried out any attacks. An earlier version of this email news alert erroneously linked to an outdated story and had an outdated headline.