Bangkok: Tensions between Thailand and Cambodia escalated dramatically on Thursday as Thai F-16 fighter jets carried out airstrikes on two Cambodian military targets amid an ongoing border dispute, the Thai army confirmed.

According to Thai Army Deputy Spokesperson Ritcha Suksuwanon, six F-16s were deployed from Ubon Ratchathani province and struck two ground targets inside Cambodian territory. The airstrikes come in response to renewed hostilities along the disputed frontier.

At least nine civilians have been reported killed in the strikes, with Thai authorities confirming 14 others injured across three border provinces. The most casualties occurred in Si Sa Ket province, where six people died after shots were reportedly fired at a gas station.

Both nations accused each other of starting the military clashes and have downgraded their diplomatic relations since Wednesday. Thailand also sealed all land border crossings with Cambodia. Relations between the Southeast Asian neighbours have deteriorated sharply since an armed confrontation in May that killed a Cambodian soldier. Nationalist passions on both sides have further inflamed the situation.

Clashes are ongoing in at least six areas along the border, Thai Defence Ministry spokesperson Surasant Kongsiri said. The first clash Thursday morning happened in an area near the ancient Ta Muen Thom temple along the border of Thailand’s Surin province and Cambodia’s Oddar Meanchey province.

A livestream video from Thailand’s side showed people running from their homes and hiding in a concrete bunker Thursday morning as explosions sounded.

Thailand’s Ministry of Foreign Affairs said Cambodia has attacked both military and non-military sites in Thailand, including a hospital.

“The Royal Thai Government calls upon Cambodia to take responsibility for the incidents that have occurred, cease attacks against civilian and military targets, and stop all actions that violate Thailand’s sovereignty. The Royal Thai Government is prepared to intensify its self-defence measures if Cambodia persists in its armed attack and violations of Thailand’s sovereignty by international law and principles,” said Nikorndej Balankura, the ministry’s spokesperson.

Cambodia's Prime Minister Hun Manet said his country has always maintained a position of peaceful resolution of problems, but “we have no choice but to respond with armed force against armed aggression.”