KABUL, Afghanistan — Afghanistan accused Pakistan of killing at least 400 people in an airstrike on a drug rehabilitation hospital in the Afghan capital late Monday. It marked a dramatic escalation of a conflict that began late last month and has seen repeated cross-border clashes as well as airstrikes inside Afghanistan. International calls for a ceasefire have gone unheeded. Pakistan dismissed the accusation that it had hit a hospital, saying its strikes, which were also conducted in eastern Afghanistan, did not hit any civilian sites. Afghanistan's deputy government spokesperson Hamdullah Fitrat, in a post on X, said the airstrike had hit the hospital in Kabul at about 9 p.m. local time, destroying large sections of the 2,000-bed facility. He said the death toll had “so far” reached 400 people, while about 250 people had been reported injured. Local television stations posted footage on X showing security forces using flashlights as they carried out casualties while firefighters struggled to extinguish flames among the ruins of a building. Fitrat said rescue teams were working