Thailand and Cambodia have traded blame for renewed clashes along their disputed border and pledged to continue the fighting, as the death toll climbs in the latest outbreak of hostilities between the neighbours.

Cambodia’s Ministry of National Defence said on Tuesday nine civilians had been killed and 20 injured since Monday, while the Thai military said four soldiers had been killed and 68 wounded on its side since clashes resumed.

Renewed fighting broke out on Sunday night, forcing hundreds of thousands of people from their homes and shattering an uneasy peace that had held since five days of clashes in July.

That bout of fighting, involving the exchange of rockets and heavy artillery fire and fuelled by competing territorial claims along their border, resulted in at least 48 deaths on both sides and the temporary evacuation of more than 300,000 civilians before a ceasefire was brokered by Malaysian Prime Minister Anwar Ibrahim and United States President Donald Trump.

Thailand, however, suspended the implementation of the ceasefire pact last month, following a landmine blast that maimed one of its soldiers.

Cambodia ‘forced to fight’

Thai Prime Minister Anutin Charnvirakul said that Cambodia had not contacted Thailand about possible negotiations and that the fighting would continue.

“We’ve got to do what we’ve got to do,” he said. “The government will support all kinds of military operations as planned earlier.”

Thailand’s military said Cambodia attacked Thai positions with artillery and rocket and drone attacks on Tuesday.

Cambodia’s powerful Senate President Hun Sen claimed in a statement on social media on Tuesday that the military had been refraining from firing at Thai forces the previous day, but had begun shooting back overnight.

He said targeting areas where Thai forces were advancing would allow Cambodia’s military to “weaken and destroy enemy forces through counterattacks”.

“Cambodia wants peace, but Cambodia is forced to fight back to defend its territory,” the former prime minister said.

Each side blames the other for firing the first shots.

‘No space for diplomacy’

In a statement on Tuesday morning, the Thai navy said it was taking action to expel Cambodian forces from its territory in the coastal province of Trat.

The navy said Cambodian forces there were increasing their presence, deploying snipers and heavy weapons, developing fortified positions and digging trenches, in what it viewed “as a direct and serious threat to Thailand’s sovereignty”, prompting the launch of operations to expel them.

Speaking to Al Jazeera, Thailand’s Foreign Minister Sihasak Phuangketkeow said Cambodia is “not ready” for peace negotiations.

“They say they’re ready on one hand, but their actions on the ground are entirely in the opposite direction,” he said.

“Diplomacy will work when the situation provides the space for diplomacy,” he said. “I’m sorry to say that right now we don’t have that space.”

Although the ongoing hostilities and military operations are bringing losses to both sides, Phuangketkeow added that “we want the Cambodian side to show that they’re ready to stop what they’re doing – and then, of course, we can consider the prospect for diplomacy and negotiations”.

Evacuees take shelter

Both sides say the renewed violence has forced large numbers of civilians on either side of the border to flee to shelter. Thailand says 400,000 people have been evacuated on its side of the border, while Cambodia says about 55,000 have relocated on its territory.

A statement from Thailand’s 2nd Army Region, situated along the border, said almost 500 temporary shelters have been set up in four border provinces.

Reporting from an evacuation centre in the town of Surin, about 40km (25 miles) from the border with Cambodia, Al Jazeera’s Rob McBride said such centres were filling up along both sides of the border, with civilians wondering when this latest bout of fighting will be over and when they will return home.

For now, he said, there appeared to be no appetite on either side to draw an end to hostilities.

“It seems both sides are content with exchanging volleys of fire across this disputed border,” he said.

Ceasefire ‘forced’

Analysts say the breakdown of the fragile ceasefire between the countries was unsurprising. To bring an end to the fighting in July, Trump had threatened to freeze negotiations for lower trade tariffs unless both sides stopped hostilities, leading to an expanded ceasefire signed in October in Trump’s presence.

Virak Ou, the founder of Cambodian think tank Future Forum, told Al Jazeera from Phnom Penh that the ceasefire was “forced” by the Trump administration, “particularly with the tariffs hanging over both countries”.

“Because of that, the ceasefire was fragile,” he said.

Phuangketkeow, the Thai foreign minister, told Reuters on Tuesday that the threat of tariffs should not be used to pressure Thailand to start talks with Cambodia to end the latest fighting, and said it was up to its neighbour to de-escalate the conflict.

“We don’t think tariffs should be used to pressure Thailand … to get back to a dialogue process,” he said.

“You have to separate the issue of Thai-Cambodia relations from the issue of the trade talks.”

For more than a century, Thailand and Cambodia have contested sovereignty at points along their 817km (508-mile) border, first mapped in 1907 by France when it ruled Cambodia as a colony.

Simmering tension has occasionally exploded into skirmishes, such as a weeklong artillery exchange in 2011, despite attempts to resolve the dispute peacefully.

A 2013 ruling by the International Court of Justice (ICJ) upheld a 1962 judgement by the same body awarding part of the land around Preah Vihear temple, a UNESCO World Heritage Site, to Cambodia and instructing Thailand to withdraw its personnel stationed in the area.