A US drone attack in Pakistan's northwestern tribal region near the Afghan border killed three insurgents on Wednesday, security officials said. "The drone fired two missiles on a vehicle and initial reports said three militants were killed," a security official said. The vehicle was hit in Isha village, about 10 kilometres (six miles) east of Miranshah, two other security officials said. Miranshah is the main town in North Waziristan, a known Taliban and Al-Qaeda stronghold. There has been a dramatic increase in US drone strikes in Pakistan since a NATO summit in Chicago ended last month without a deal to end a six-month blockade on NATO supplies crossing into Afghanistan. A drone attack killed 15 militants in North Waziristan on June 4. The dead included senior Al-Qaeda figure Abu Yahya al-Libi. It was not immediately known if there were any high-value targets killed in the latest strike.