NEW DELHI: Thailand and Cambodia traded heavy artillery fire, marking the second consecutive day of their most intense border conflict in over a decade, despite growing international calls for an immediate ceasefire.

The renewed hostilities have left at least 16 people dead and forced the evacuation of over 100,000 civilians from Thailand’s Ubon Ratchathani and Surin provinces. Thai military officials reported pre-dawn clashes and accused Cambodian forces of deploying field artillery and Russian-made BM-21 multiple rocket launchers.

“Cambodian forces have launched sustained bombardment using heavy weapons, including BM-21 rocket systems,” the Thai military said in a statement. “Thai forces have returned fire in line with tactical requirements.”

The conflict, rooted in a long-standing border dispute, flared up near a contested area, rapidly escalating from sporadic small arms fire to full-scale shelling across at least six locations spanning 209 km (130 miles) of the frontier.

Both sides have blamed each other for initiating the violence.