Pakistan said Tuesday 35 Islamist militants were killed in an overnight ground and air offensive in the crisis-hit Swat valley, where around 20,000 civilians have fled pitched battles in a week. Until two years ago, Swat was a jewel in the crown of Pakistani tourism, frequented by foreign and local holidaymakers escaping to the mountains for skiing in winter or more refreshing climes in the punishing heat of summer. But the northwest region descended into chaos after radical cleric Maulana Fazlullah embarked on a terrifying campaign to enforce a Taliban-style Sharia law, prompting thousands of people to flee and suffocating day-to-day life. Pakistan, under massive Western pressure to clamp down on extremists, last week stepped up an offensive in an attempt to flush out the militants and wrest back control of Swat, which locals say has fallen to the insurgents.