Thailand’s military accused Cambodian forces on Wednesday of breaching a ceasefire agreement at three separate locations along the disputed border, warning that continued aggression could compel Thai forces to respond more decisively.

The allegations come less than two days after both governments agreed to a ceasefire brokered in Malaysia, which came into effect at midnight on Monday, aimed to stop fighting and prevent escalation of their deadliest conflict in more than a decade following five days of intense fighting that has killed at least 43 people and displaced over 300,000 civilians on either side.

The truce came after a sustained push from Malaysian Premier Anwar Ibrahim and US President Donald Trump, with the latter warning Thai and Cambodian leaders that if fighting continued.

Thailand and Cambodia face a tariff of 36% on their goods in the U.S., their biggest export market, unless a reduction can be negotiated. After the ceasefire deal was reached, Trump said he had spoken to both leaders and instructed his trade team to tariff talks.

On Wednesday, Thailand said Cambodian forces fired on positions in northeastern Thailand’s Sisaket province on Cambodia’s northern border.

“Cambodian forces used small arms and grenade launchers, prompting Thailand to respond in self-defence,” Thai army spokesman Major-General Winthai Suvaree told reporters.

“This was the second incident since the agreement and reflects a behaviour that does not respect agreements, destroys de-escalation efforts and hampers trust between the two countries.”

Cambodia rejected the allegations, saying it was committed to the ceasefire and called for observers.

“Cambodia strongly rejects the ceasefire accusations as false, misleading and harmful to the fragile trust-building process,” Cambodian Foreign Ministry spokesperson Chum Sounry told reporters at a press conference, adding the government supports a monitoring mechanism and independent observation.

The ceasefire, which also agreed to halt troop movement, paves the way for a high-level military meeting that includes defence ministers on August 4 in Cambodia. There have been no reports of any exchange of heavy artillery fire but also no reports of troop withdrawals by either side.