Mali's military and allied militias killed at least 31 people in attacks on two villages in the central Segou region, where the main insurgent group linked to al-Qaeda operates, Human Rights Watch said in a report on Tuesday.The first attack took place on October 2 in the village of Kamona, where the army and militia forces killed at least 21 men and burned homes, the HRW report said. The second, it reported, occurred in the village of Balle about 55 km (34 miles) away, where at least 10 people,