United Nations (UN) secretary-general Ban Ki-moon on Sunday called for an immediate end to escalating violence in Thailand, and urged all sides to engage in meaningful dialogue toward ending the crisis.

Ban condemned the escalation of violence in Thailand over the past week in particular armed attacks against protesters in which even children have been killed, Xinhua news agency reports a statement as saying.

"The secretary-general believes strongly that there should be no place for violence by any side in resolving political differences and disputes," the statement said.

The UN chief urged the parties to respect human rights and the rule of law, prevent any new attacks and engage in meaningful dialogue toward ending the crisis and advancing reform.

Thailand has seen sporadic violence since political unrest erupted in late 2013.

Protesters are seeking to overthrow Prime Minister Yingluck Shinawatra's administration and to implement anti-corruption reforms.

At least 24 people, including three children, were injured in a bomb explosion near an anti-government protest site in the Thai capital of Bangkok on Sunday afternoon.

On Saturday night, unidentified attackers shot and threw grenades at a protest site in east Thailand's Trat province that left a five-year-old girl dead and 34 others injured.