China has dismissed allegations that it was supplying weapons to Cambodia amid its ongoing border conflict with Thailand that has led to at least 33 people dying and hundreds of thousands displaced.

The deadly conflict on the Thai-Cambodian border pits a longtime United States ally with decades of experience against a relatively young armed force with close ties to China.

As fighting spread to at least six areas along the arcane frontier, Thailand’s military closed crossings between the countries. The fighting spurred at least 40,000 civilians from more than 80 villages near the border to flee to makeshift bomb shelters of sandbags and car tires.

Thailand and Cambodia exchanged heavy artillery fire for a second day on Friday as their worst fighting in over a decade intensified and spread to new areas.

Thailand and Cambodia exchanged heavy artillery fire for a second day on Friday as border fighting intensified and spread, while Cambodia's leader said Thailand had agreed to a Malaysian ceasefire proposal but then backed down.

The UN Security Council held an emergency closed-door meeting Friday in New York. Malaysia, which chairs the 10-nation regional bloc that includes both countries, called for an end to the hostilities and offered to mediate.