BANGKOK—Bombers set off at least 13 blasts in a town in southern Thailand overnight, and police killed two suspected insurgents in a separate raid after a 20-hour siege in a nearby province, authorities said on Saturday. While officials did not link the two incidents directly, the violence came weeks after the government reopened a dialogue with insurgents from a Malay-Muslim minority in the southern part of the country. The siege took place in Narathiwat province, where a combined force of soldiers and police surrounded a house in the Ra-ngae district on Friday, following a tip-off that suspects linked to bomb attacks last year were hiding inside. Authorities said they tried to negotiate with the suspects, before finally raiding the house. One volunteer ranger was hurt and the two suspects killed in the raid. Separately, one person was injured when at least 13 small explosions struck the town of Yala late …