Clashes between the armed forces of Thailand and Cambodia along their disputed border area have widened since erupting on Thursday.

Thai health authorities say 11 civilians and one soldier have died and more than 30 have been injured in Thailand.

A convenience store and a hospital in Thailand came under shelling from Cambodia.

The Thai military says its fighter jets have attacked Cambodian forces. There have been no reports about damage on the Cambodian side.

The Thai government is calling on residents in areas near the border to evacuate. More than 100,000, mainly residents, have fled.

Schools and other shelters have been accepting people who left their homes.

The two countries have long fought for territorial rights in border areas. Tension has risen since a gunfight occurred in May, leaving one Cambodian soldier dead.

A spokesperson for the Thai military accused Cambodia of the latest attack and said that Thailand will use all of its capabilities to defend its sovereignty.

Cambodian Prime Minister Hun Manet has requested an emergency meeting of the United Nations Security Council, and said armed forces have to be used in response to military attacks.

A spokesperson for the UN Secretary-General said on Thursday that Antonio Guterres "urges both sides to exercise maximum restraint and address any issues through dialogue and in a spirt of good neighborliness, with a view to finding a lasting solution to the dispute."

A spokesperson for the US State Department issued a statement on Thursday, saying, "The United States is gravely concerned by reports of the escalating fighting along the Thailand-Cambodia border." It added, "We strongly urge the immediate cessation of attacks, protection of civilians, and peaceful settlement of disputes."