Large parts of downtown Bangkok have turned red, where tens of thousands of opposition supporters - part of a Red Shirt movement - are demanding the government's removal and fresh elections.
The Red Shirts are supporters of Thaksin Shinawatra, the country's deposed prime minister, and they want political change now.
The demonstrators have warned that they will press ahead with their agitation until their demands are met - even if it means "paralysing" Bangkok.
Al Jazeera's Wayne Hay reports from Bangkok, where about 50,000 troops have been deployed.
Source: Al Jazeera