KABUL : Nearly 80 Afghan police have died every week during the current fighting season, officials said Tuesday, as the national security forces take on the battle against Taliban militants. The figures, which are in addition to Afghan soldiers killed, reflect a sharp rise in casualties at a time when US-led NATO forces are stepping back from the frontline and steadily withdrawing 87,000 troops by the end of next year. Afghanistan’s fighting season traditionally begins in April or May as snow melts in mountains, and slows in November, when winter sets in.