Natdanai Chuchan, an 8-year old boy son of Prakong Chuchan, a protester who was killed in the bomb blast on Friday, cries after seeing the body of his father, center, before a memorial service at Rama hospital in Bangkok, Thailand Sunday, Jan. 19, 2014. Friends and relatives of Prakong Chuchan, a protester who was killed in Friday's bomb blast, cry over his body before a memorial service at Rama hospital in Bangkok, Thailand Sunday, Jan. 19, 2014. Thai anti-government protesters celebrate as a police pick up truck runs out of the prime minister's office of government house Sunday, Jan. 19, 2014 in Bangkok, Thailand. Police on Sunday withdrew a number of their unit out of the government house compound under the request of protesters. BANGKOK (AP) - Two explosions shook an anti-government demonstration site in Thailand's capital on Sunday, wounding at least 28 people in the latest violence to hit Bangkok as the nation's increasingly bloody political crisis drags on. The demonstrators, who control several small patches of Bangkok, are vying to overthrow Prime Minister Yingluck Shinawatra's government and derail Feb. 2 elections she called to quell the crisis. The protest movement has refused to negotiate and the rising casualty toll has only deepened the deadlock. The first blast went off about 100-200 meters (yards) from a stage set up by protesters, leaving a small crater beside a small shop. The second went off near a row of vendors selling anti-government T-shirts in the street, leaving bloody clothes and a ripped white-and-blue plastic tarp scattered across the ground. Protest leader Thaworn Senniem said the attacker, a man, was aiming at him but the first grenade bounced off a tree and exploded near protesters. He said the suspect ran, threw a second grenade, and was chased down an alley, where he fled on a motorcycle. Although the vast majority of Bangkok remains calm, political violence nearly every day over the last week has kept the city of 12 million on edge and raised fears hostilities are only just beginning. On Friday, a grenade hurled at marching demonstrators in central Bangkok killed one man and injured dozens. Then late Saturday, a gunman opened fire on protesters in the capital's Lad Prao district, seriously wounding a 54-year-old volunteer guard who was shot in the back. There are conflicting theories about who is behind the unrest. Demonstrators blame the government and its supporters, who in turn accuse protesters of staging the attacks to pressure the military or judiciary to intervene - scenarios that would benefit the protest movement, which lacks the numbers to bring down the government on its own. Sunai Phasuk, a senior researcher for Human Rights Watch, said "both sides of Thailand's political divide use violence and spin to serve their political goals." Such attacks are likely to continue, he added, which will "make the situation worse by deepening mistrust and escalating tension between the two sides." The last coup, in 2006, toppled then-Prime Minister Thaksin Shinawatra - Yingluck's brother - and touched off a societal schism that in broad terms pits a poor northern majority who back the Shinawatras against an urban-based elite backed by the army and staunch royalists who see Yingluck's family as a corrupt threat to the traditional structures of power. Sunday's blast wounded 28 civilians, five of them critically, according to the Erawan Medical Center, which tracks casualties. Police Col. Kamthorn Auicharoen, an explosive ordnance disposal officer, said intact grenades levers found at the scene indicated the explosives were Russian-built, anti-personnel RGD-5s. Sunai called on police to find the perpetrators, saying that "up until now, we haven't seen any serious investigation into these attacks." But he also said police have had trouble probing the blasts. They are largely kept away from protest sites, and after Friday's attack, they were prevented from accessing the area "by protesters who see them as a partial party that is working for the government." Police were able to enter the blast zone Sunday swiftly, but the area was tense and they were cursed and booed. A senior member of the protest movement, Sathit Wongnongtoey, condemned the bloodshed but said "condemnation is not enough ... it's the government who did it." Yingluck's administration and the political movement that supports her, the Red Shirts, have denied responsibility for organizing the violence. Anxious about triggering military intervention, Yingluck has ordered police to avoid confrontations. The strategy, however, has undermined rule of law and the government's authority, with police essentially ceding scattered pockets of Bangkok to demonstrators. The protest movement has armed guards, and it has taken the law into its own hands. Another protest leader, Issara Somchai, said demonstrators detained two men Saturday allegedly found with small homemade explosives and handcuffs. He said the men were being "investigated." They are safe with us," he said, adding that the pair was also being protected from demonstrators who could seek revenge.