Bangkok: Thailand`s capital was tense on Saturday after a night of fighting that killed 16 people and wounded 141 as troops struggle to isolate a sprawling encampment of protesters seeking to topple the government.
Thundering grenade explosions and sporadic gunfire echoed across central Bangkok until nearly dawn as the Army battled to set up a perimeter around a 3.5 sq-km (1.2 sq-mile) protest site defiant red-shirted demonstrators refuse to leave.
UN Secretary-General Ban Ki-Moon expressed concern over "the rapidly mounting tensions and violence”.
"He strongly encourages them to urgently return to dialogue in order to de-escalate the situation and resolve matters peacefully," his spokesman said in a written statement.
The Canadian government urged a return to talks following the violence after a Bangkok-based Canadian journalist was shot three times, one of three journalists wounded in fighting on Friday that spiralled into chaotic urban warfare.
The government said on Friday it would restore order "in the next few days" as the city of 15 million people braced for a crackdown to end a six-week protest by thousands of "red shirts" packed into an area of high-end department stores, luxury hotels, embassies and expensive residential apartments.
The crisis has paralysed parts of Bangkok, squeezed Southeast Asia`s second-biggest economy and scared off tourists.
Troops fired tear gas, rubber bullets and live rounds at defiant protesters who fought back with petrol bombs, stones and home-made rockets. They set vehicles on fire and rolled burning tires into checkpoints of troops.
The Army said the protesters were firing handguns and M-79 grenades. Army spokesmen Sansern Kaewkamnerd said there were an estimated 500 armed "terrorists" among the thousands of protesters in the city.
A source close to Army Chief Anupong Paochinda said more troop reinforcements would be deployed, fearing more protesters would arrive to surround and attack soldiers.
"It`s unlikely to end quickly. There will be several skirmishes in the coming days but we are still confident we will get the numbers down and seal the area," the source said.
Protesters remain defiant
The protesters are showing no sign of leaving. The number of casualties is expected to keep rising, deepening a crisis that began with festive rallies on March 12 and descended into Thailand`s deadliest political violence in 18 years.
Before fighting began on Thursday with the shooting of a renegade general allied with the protesters, the two-month crisis had already killed 29 people and wounded about 1,400 -- most of whom died during an April 10 gun battle in Bangkok`s old quarter.
The protesters are barricaded behind walls of kerosene-soaked tires, sharpened bamboo staves, concrete blocks and razor wire.
The fighting is the latest flare-up in a polarizing five-year crisis between a royalist urban elite establishment, who back Prime Minister Abhisit Vejjajiva, and the rural and urban poor who accuse conservative elites and the military`s top brass of colluding to bring down two elected governments.
Those governments were led or backed by exiled former premier Thaksin Shinawatra, a graft-convicted populist billionaire ousted in a 2006 coup who is a figurehead of the protest movement.
The red shirts and their supporters say the politically powerful military influenced a 2008 parliamentary vote, which took place after a pro-Thaksin party was dissolved, to ensure the British-born, Oxford-educated Abhisit rose to power.
They have repeated their demand for Abhisit to call an immediate election and say he should take responsibility for violence that is also rattling investors.