Updated

The father grimaced and wept as he struggled to contain his grief at the death of his two children in a grenade attack during a weekend trip to a mall in downtown Bangkok — the latest casualties in Thailand's months of political crisis.

"I'm asking and pleading to every side to let my children be the last case (of violence) on Thai soil," Tayakorn Yos-ubon, 33, said, his voice shaking, before retrieving their bodies from the morgue Monday.

The 4- and 5-year-old children were not part of the anti-government demonstrations. They had piled into a three-wheeled "tuk-tuk" taxi after eating at a KFC with their aunt when the attack occurred Sunday near a busy intersection occupied by the protesters.

They, along with 5-year-old girl who died Saturday in another attack on a rally site in the eastern province of Trat, are the first children to be killed in the country's latest round of political unrest, which has claimed at least 20 lives and injured more than 700 since November. Police have not arrested any suspects in the weekend attacks.

The Thai public has recoiled in shock over the children's deaths, and yet there seems to be no sign that either side in the impasse is softening its position. City residents have braced for more violence.

Protesters, mostly representing the urban elite and those in the south, are pressing for the resignation of Prime Minister Yingluck Shinawatra. They want her to be replaced by an appointed interim government to implement reforms they say are needed to fight corruption and permanently remove Yingluck's family from politics.

Thailand has seen sometimes-violent political conflict since 2006, when then-Prime Minister Thaksin Shinawatra, Yingluck's wealthy brother, was ousted by a military coup after being accused of corruption and abuse of power. Thaksin's supporters and opponents have since taken to the streets for extended periods in an ongoing power struggle.

Yingluck, who has strong backing from the rural poor majority, condemned the weekend attacks and said the country would suffer more pain if the two sides don't negotiate.

"It's time we make an effort to talk together, and each side must stop turning away from the other," she said.

The protesters, who are closely backed by the opposition Democrat Party, have refused to negotiate.

The country's army commander-in-chief also urged a negotiated solution to the standoff, saying the military would not intervene despite the violence.

"What needs to be done urgently is for each side to talk and discuss, to make sure they will receive fairness and move toward a solution methodically and peacefully," Gen. Prayuth Chan-ocha said.

In 2010, pro-Thaksin "Red Shirts" occupied part of Bangkok for two months and were assisted by their own armed militia. More than 90 people were killed in violent confrontations, with the army finally sweeping away the demonstrators.