Anti-government protesters wave flags as one of their leaders addresses them at the Finance Ministry, which they have occupied since Monday, in Bangkok November 26, 2013. Nearly 3,000 flag-waving anti-government protesters massed in front of Thailand's Interior Ministry on Tuesday, intensifying pressure on Prime Minister Yingluck Shinawatra a day after they stormed compounds of two other ministries. [Photo/Agencies]

Protesters in Thailand forced the closure of several government ministries on Tuesday and said they would take control of state offices nationwide as they seek to oust Prime Minister Yingluck Shinawatra, escalating the biggest challenge she has faced since taking office.

Police issued an arrest warrant for protest leader Suthep Thaugsuban, a former opposition lawmaker, who led the storming of the Finance Ministry a day earlier. But police said Suthep would not be arrested at the rally, as part of a pledge to avoid clashes with protesters.

Protesters say they want Yingluck, who took office in 2011, to step down amid claims her government is controlled by her brother, former prime minister Thaksin Shinawatra.

The protests are harmful for the country's domestic development and its reputation in the region, observers said.

"As the second-largest economy in Southeast Asia, Thailand plays a key role in regional development," said Song Qingrun, a Southeast Asian studies researcher at China Institutes of Contemporary International Relations.

Thailand is also an important regional coordinator for China to develop ties with the Association of Southeast Asian Nations, so Thai domestic unrest also undermines the cooperation between China and ASEAN, he added.

"The fundamental conflict between the Thai government and protesters is actually a fight between Thaksin supporters and his opponents for the leading power and related interests," Song said.

"So far, both sides still remained nonviolent, which is much better than the bloody protests in earlier years," Song added.

Demonstrators surrounded the Interior Ministry and then cut electricity and water to pressure people inside to leave. Security personnel locked themselves behind the ministry's gates, with employees still inside.

The unrest takes place during the most popular travel season for international tourists, including Chinese, and the protests, which have blocked roads and public facilities, is damaging the country's tourism economy, said Zhou Fangye, an expert on Thai studies at the Chinese Academy of Social Sciences.

"Since early next month will be the Thai king's 86th birthday, the protests may not last longer than a week," Zhou said.

If the protests continue during King Bhumibol's birthday, Suthep and his Democratic Party will see waning support at the upcoming national election early next year, Zhou added.

AP-China Daily

Zhao Yanrong in Beijing contributed to this story.

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