BANGKOK - Thai opposition protesters marched on key state communications targets Saturday after vowing a final push to topple the government, as the capital braces for mass rival rallies.
Defiant demonstrators have besieged key government buildings in Bangkok in the biggest street protests since mass rallies in 2010 degenerated into the kingdom's worst civil strife in decades.
The protesters - a mix of royalists, southerners and the urban middle class sometimes numbering in their tens of thousands - are united by their loathing of former premier Thaksin Shinawatra.
The controversial former telecoms tycoon was ousted in a military coup in 2006 and lives in self-imposed exile, but he is widely believed to be the real power behind the embattled government of his younger sister Yingluck Shinawatra.
Several thousand anti-government protesters were scattered across five bases in the capital Saturday, according to city police.
But turnout is expected to spike over the weekend as organisers seek a final push ahead of celebrations for revered King Bhumibol Adulyadej's birthday on December 5, which is traditionally marked in an atmosphere of calm and respect.
They have declared Sunday a "day of victory", with plans to gather near the heavily guarded Government House, besiege more important buildings - even Bangkok's zoo - and to tighten their blockade of government ministries.
Protesters on Saturday began surrounding offices of Telephone Organisation of Thailand (TOT) and Communications Authority of Thailand (CAT), two key state telecoms firms.
"We will control the area, like we did at the finance ministry, and ask staff not to work. So on Monday everything will shut down," rally spokesman Akanat Promphan told AFP.
But the ICT ministry insisted that back-up systems were in place and communications in Thailand would not be affected.
Protesters are demanding the end of the "Thaksin regime" and want to replace the government with an unelected "people's council".