A powerful bomb exploded Saturday at a gathering in a remote town in southwestern Pakistan, killing at least 15 people and wounding 25 others, police said. Thousands of people had gathered near the town of Naseerabad, about 350 kilometers (210 miles) south of Quetta, when the bomb went off outside, said Merab Khan, a local police official. There was no immediate claim of responsibility for the attack, and police said they were investigating. Khan said the dead and injured, some in critical condition, were transported to a nearby hospital. He said he expected the death toll to rise.