BANGKOK (AP) ― Gunmen in a pickup truck attacked an antigovernment protest in Thailand’s east, killing at least one person, a child, and wounding dozens, as violence in the country’s 3-month-old political crisis spread outside the capital, Bangkok, officials said Sunday.

The attack took place Saturday night in Trat province, about 300 kilometers east of Bangkok, where about 500 protesters demanding the resignation of Prime Minister Yingluck Shinawatra were holding a rally near food stalls where people were dining. 

Thai media reported that as many as three people were killed and several others are in critical condition, but National Security Council chief Lt. Gen. Paradorn Pattanathuabutr said there had been one fatality ― an 8-year-old girl. A nurse at Trat Hospital, Nantiya Thientawatchai, said that the girl who died was 5 years old. The reason for the discrepancy was not clear.

The attack was the latest in a string of protest-related violence roiling Thailand over the past three months, in which at least 16 people have been killed and hundreds hurt. The protesters want Yingluck to quit to make way for an appointed interim government to implement anti-corruption reforms, but she has refused.

Police Lt. Thanabhum Newanit said unidentified assailants in a pickup shot into the crowd and two explosive devices went off. It was not clear if the protest group, which uses armed guards, fought back. He and other officials said that about three dozen people were hurt.

Both supporters and opponents of the protest group called the People’s Democratic Reform Committee, as well as police, have been victims of the political violence, which before Saturday was mostly confined to the Thai capital. On Friday night, six people were hurt when unknown attackers threw a grenade into a protest crowd in Bangkok.

Both sides in the ongoing political dispute have blamed the other for instigating violence.

“At this point we do not know who was behind the attack, but there are several factors to take into account in the investigation,” Paradorn said.

He added that the protesters in Trat have been rallying for a long time, “so they might have caused disturbance to others. And that area is controlled by groups that are affiliated with the anti-government side,” he said.

“The prime minister has expressed concern and urged the national police chief to speed up the investigation,” Paradorn said.

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

In 2010, pro-Thaksin “Red Shirts” occupied part of Bangkok for two months. When the army was called out to control them, more than 90 people were killed in violent confrontations.

The Red Shirts have mostly kept a low profile during the current political unrest, but as Yingluck faces what her supporters feel are unfair court rulings loosening her grip on power, there are fears they will take to the streets again. The courts are widely seen as being based against Thaksin’s political machine.

Thaksin and his allies have won every national election since 2001, with his sister taking office in 2011 with a majority of parliamentary seats.

Yingluck called early elections to try to reaffirm her mandate, but the protesters disrupted February polling, which has yet to be completed, leaving Thailand with a caretaker government. She also faces several legal challenges that could oust her from office.