Thailand has officially submitted a letter to the United Nations Security Council (UNSC), presenting evidence that Cambodia initiated the armed conflict in the latest exchanges of gunfire between the two countries.

The United States, China and Japan have expressed grave concern and urged de-escalation following renewed clashes between Thailand and Cambodia, while France also joined the call for an immediate cessation of hostilities and a peaceful resolution.

Acting Prime Minister Phumtham Wechayachai on Friday condemned Cambodia for committing serious war crimes by firing at Thai communities and hospitals and urged the international community to join in condemning these actions while martial law was expanded.

Areas up to 40 kilometres inland from the border in five districts in Si Sa Ket and Ubon Ratchathani provinces are considered risky as they fall into the firing ranges of rockets deployed by Cambodian forces, the Royal Thai Army said on Friday.

National oil and gas conglomerate PTT Plc has decided to adjust its investment in the life science business by selling a small portion of the shares it holds in Taiwan-based Lotus Pharmaceutical to boost financial flexibility.

SURIN — Thailand and Cambodia exchanged heavy artillery on Friday as their worst fighting in more than a decade stretched for a second day, despite calls from the region and beyond for an immediate ceasefire in an escalating border conflict that has killed at least 15 people.