The Department of Foreign Affairs is advising against all non-essential travel to Thailand because of the current political unrest.
Britain has also urged its citizens to avoid non-essential travel due to 'violent incidents of an unpredictable nature'.
Thai troops opened fire on 'Red Shirt' protestors during a tense confrontation on a motorway in Bangkok's northern suburbs that left one soldier dead and 18 people injured.
The army said it had used real bullets in the latest standoff in the capital.
'Real bullets were used because soldiers and police are human and protestors attacked officials first,' said army spokesman Sansern Kaewkamnerd.
Protestors threw rocks at soldiers and riot police who used razor wire to block their convoy on a major road heading out of the city.
One soldier died from a gunshot wound to the head during the clashes, while two more soldiers and 16 civilians were wounded.
The Reds Shirts accused troops of using 'war weapons' against them and said the soldier was a victim of friendly fire.
The clashes broke out near Bangkok's second airport Don Mueang International, which is about 25km from the main rally site and handles mostly charter and domestic flights.
The Red Shirts want immediate elections to replace Prime Minister Abhisit Vejjajiva's government.
So far this month, 27 people have died and almost 1,000 have been injured in the worst political unrest in almost two decades.
