BANGKOK, Thailand -- Bangkok police on Tuesday began removing concrete barriers and barbed wire around their headquarters after agreeing to let anti-government protesters into the building ahead of a threatened assault.

Reporters saw cranes lifting the concrete panels at the Sri Ayutthaya Road in the historic part of the city as protest leaders gave speeches from trucks.

The unexpected move was apparently aimed at avoiding further clashes between the two sides that have left at least three people dead and more than 220 people injured since this weekend.

On Monday night, protest leader Suthep Thaugsuban told his supporters to storm the Bangkok Metropolitan Police Bureau, one of the main buildings they have vowed to seize as part of a campaign to topple the government of Prime Minister Yingluck Shinawatra.

At the same time, Yingluck told a news conference that while she is willing to do anything it takes to end the violent protests, she cannot accept Suthep's demand to hand power to an unelected council. Yingluck was elected with an overwhelming majority in 2011, and many observers see the protesters' demand as unreasonable if not outlandish.

The two opposing stands highlight the unusual political deadlock that is undermining democracy in Thailand with no clear solution in sight. The protests have renewed fears of prolonged instability in Southeast Asia's second-biggest economy and come just ahead of the peak holiday tourist season.

In some of the worst clashes since the protests began last week, protesters on Monday commandeered garbage trucks and bulldozers, and tried to ram concrete barriers at the Government House and other key offices. Police repelled them by firing tear gas, water cannons and rubber bullets, as protesters shot back explosives from homemade rocket launchers.

The protesters, who are mostly middle-class Bangkok supporters of the opposition Democrat Party, accuse Yingluck of being a proxy for her brother, former Prime Minister Thaksin Shinawatra. He was deposed in a 2006 military coup but remains central to Thailand's political crisis, and is a focal point for the protester's hatred.

The protesters say their goal is to uproot the political machine of Thaksin, who is accused of widespread corruption and abuse of power.

The violence has largely been around key institutions -- the Government House, the Parliament and Metropolitan Police Bureau in the historic quarter of the capital. The area has some of Bangkok's main tourist attractions such as the Grand Palace, Wat Pho temple, the Bangkok zoo, and the backpacker area of Khao San Road. Most of Bangkok, a city of 10 million, has been unaffected.

Yingluck and Suthep met briefly on Sunday in the presence of top military leaders, even though he had an arrest warrant against him. A second arrest warrant was issued Monday on charges of insurrection. His sustained campaign has raised suggestions that he may have the backing of the military, which has long had a powerful influence over Thai politics. The army has often stepped in during times of crisis, carrying out 18 successful or attempted coups since the 1930s.

Political instability has plagued Thailand since the military ousted Thaksin, who remains hugely popular among rural voters, in 2006. Two years later, anti-Thaksin protesters occupied Bangkok's two airports for a week after taking over the prime minister's office for three months, and in 2010 pro-Thaksin protesters occupied downtown Bangkok for weeks in a standoff that ended with parts of the city in flames and more than 90 dead.