BANGKOK — A 5-year-old girl was killed and 37 people wounded in an attack on an anti-government protest rally in the eastern Thailand province of Trat, police said Sunday.

The assailants arrived in two pickup trucks at the rally in Khao Saming district, about 200 kilometers (about 125 miles) east of Bangkok, firing guns and grenades at the crowd on Saturday night, Trat Police Lieutenant Kanapum Naewawit said by phone.

Ekkanat Promphan, spokesman for the People’s Democratic Reform Committee, demanded the government of caretaker Prime Minister Yingluck Shinawatra accept responsibility for the attack.

“This attack was done by people who disagree with the PDRC in what was clearly a well-organized strike using M16s and grenades,” Ekkanat said.

“The reason there continue to be attacks on our rally sites is because the government does nothing to prevent them and has failed to find anyone culpable for past incidents of violence,” he said. “It’s time for the government to take responsibility for these attacks.”

The PDRC has been leading anti-government protests, mainly in Bangkok, since early November, demanding the premier’s resignation to pave the way for an appointed government and political reform.

At least 16 people have died in protest-related violence and about 700 have sustained injuries, according to government and media sources.

In a police crackdown on the protesters Tuesday, one officer and four demonstrators were killed.

• MCT Campus