According to a recent report (published on 2014 January 20), the violence in Thailand continues. There have been explosions and gunfire.
Although we do not know, with certainty, the background of the assailants who tossed the grenades and who fired the guns, we can make an educated guess. Suthep Thaugsuban wants the military to stage a coup ousting Yingluck Shinawatra, and any large-scale violence will be used by the military to justify seizing control of Thailand. At the same time, the death of Thaugsuban (and other key members of the Democrat Party), the royal family (including the king), and the royalist soldiers would help the Thai people by preventing the overthrow of a democratic government.
Given these facts, the conclusion is obvious. If the violence (via the explosions and gunfire) had actually killed Thausuban, the king, the royalist soldiers, and other prominent impediments to the Westernization of Thailand, then a member of the pro-democracy group (known as the "Red Shirts") likely committed the violence.
Yet, the recent spate of violence did not remove these prominent roadblocks to Westernization but, instead, killed some ordinary citizens of Thailand. Therefore, a member of the anti-democracy group (known as the "Yellow Shirts" and lead by Thaugsuban) likely committed the violence. The members of the anti-democracy group are staging this violence and are sacrificing some of the supporters of Thaugsuban in order to lure the military into overthrowing the government of Shinawatra.