Long-festering tensions over border territory have escalated into armed conflict between Cambodia and Thailand, leading to dozens of deaths on both sides and displacing tens of thousands of people.

Thailand has mobilised gunboats to patrol its province bordering Cambodia as conflict between the two nations enters the third day, with death toll climbing to 33 and tens of thousands seeking refuge.

Thailand and Cambodia traded accusations of fresh attacks Saturday as deadly border clashes entered a third day and international pressure mounted for a ceasefire. The fighting has killed at least 33 people and displaced more than 168,

The tank screeches as it rolls into the ad-hoc military base before four battle-weary soldiers jump out to re-inspect the hefty vehicle.

Thailand said its navy joined the army in repelling Cambodian attacks along the border, as fighting spread to new areas on the third day of a conflict that has killed more than 30 people.

Cambodian officials are reporting 12 new deaths in its fighting with Thailand, bringing death toll on both sides to 32