SAMRAONG, Cambodia (AFP) — Thailand and Cambodia clashed for a third day on Saturday, as the death toll from their bloodiest fighting in years rose to 33 and Phnom Penh called for an “immediate ceasefire.”

A long-running border dispute erupted into intense conflict involving jets, artillery, tanks and ground troops on Thursday, prompting the United Nations Security Council to hold an emergency meeting on the crisis Friday.

Cambodia’s defense ministry said 13 people were now confirmed killed in the fighting, including eight civilians and five soldiers, with 71 people wounded.

In Thailand, the army said five soldiers were killed on Friday, taking the toll there to 20 — 14 civilians and six military.

The death toll across the two countries is now higher than the 28 killed in the last major round of fighting between 2008 and 2011.

Both sides reported a clash around 5 a.m., with Cambodia accusing Thai forces of firing “five heavy artillery shells” into locations in Pursat province, which borders Thailand’s Trat province — on the coast some 250 kilometers southwest of the main frontlines.

Agence France-Presse journalists in the Cambodian town of Samraong, near the ridge of forest-clad hills that marks the border and has seen the bulk of the fighting, heard the thump of artillery early Saturday afternoon.

A Thai villager reached by phone as he sheltered in a bunker in Sisaket province, just 10 kilometers from the frontier, also reported hearing artillery.