Thailand and Cambodia exchanged heavy artillery fire 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 16 people.

Thailand has launched airstrikes against Cambodian military targets along their disputed border, in an escalation of their deadly border dispute. Follow for live updates

Tensions have bubbled between the two neighbors for months, flaring on Thursday as Cambodia and Thailand exchanged fire.

Britain's foreign ministry on Thursday has advised against all but essential travel to parts of Cambodia and Thailand following the worst fighting between the countries in 13 years.