MIRANSHAH, Pakistan, June 19 (Reuters) - A missile attack, possibly launched by U.S. forces in Afghanistan, killed at least 32 pro-Taliban militants on Tuesday in a Pakistani tribal region near the border, Pakistani officials said. The missiles targeted a militant training base in Mamy Rogha, a village near Datta Khel district, 60 km (40 miles) west of Miranshah, the main town in North Waziristan, the officials, speaking on condition of anonymity, told Reuters. "There was a cluster of three houses and a tent which were hit. There were about 45 people in that area," a senior government official told Reuters. A Pakistani military spokesman confirmed an "explosion" in the area, but said the Pakistani army had not launched any operations there.