India’s embassies in Thailand and Cambodia have asked Indian citizens not to travel to the border areas of the two countries amid clashes between Bangkok and Phnom Penh.

The diplomatic mission in Cambodia on Saturday issued an advisory urging Indians to avoid going to the border areas. The embassy also shared emergency contact details for Indian citizens requiring assistance.

“In case of any emergency, Indian nationals may approach the Embassy of India, Phnom Penh at +855 92881676 or email cons.phnompenh[at]mea.gov.in,” it added.

This came a day after the Indian embassy in Thailand advised Indian travellers to check updates issued by Thai authorities.

A link to an update shared by the Tourism Authority of Thailand said that “border zones” had been affected in seven provinces because of restrictions and that martial law had been imposed in select districts.

These places are not recommended for travelling, the Indian embassy quoted the Thai tourism authority as saying.

The advisories came amid the worst border conflict between Thailand and Cambodia in 13 years. Fighting, which began on Wednesday, has involved heavy artillery, air strikes and rocket fire across several disputed border areas.

At least 33 persons have been killed in the conflict.

Of the 13 deaths in Cambodia, eight were civilians and five soldiers. In Thailand, six military personnel and 14 civilians were killed, AFP reported.

While Bangkok has accused Phnom Penh of targeting civilians and using rockets, Cambodia has condemned Thailand’s alleged use of cluster munitions, Reuters reported.

The fighting marks a sharp escalation in a long-running dispute between the countries that contest several stretches of land along their border. At least 28 persons had died in previous clashes between 2008 and 2011.

A 2013 United Nations court ruling had largely eased tensions. But the current crisis was triggered in May after a Cambodian soldier was killed in a fresh clash, AFP reported.