Protesters forced their way onto the grounds of Thailand’s army headquarters on Friday, asking the military to support their increasingly aggressive campaign to topple Prime Minister Yingluck Shinawatra. The army insisted it will not take sides in the dispute.

In a letter addressed to the army chief, the protesters stopped short of calling for a coup but urged military leaders to “take a stand” in Thailand’s spiraling political crisis and state which side they are on. The crowd of 1,200 people stayed on the sprawling lawn of the Royal Thai Army compound for two hours before filing out peacefully.

Army commander Gen. Prayuth Chan-ocha responded with a call for the protests to be democratic and law-abiding.

“Don’t try to make the army take sides because the army considers that all of us are fellow Thais, so the government, state authorities and people from every sector must jointly seek a peaceful solution as soon as possible,” Prayuth said in a statement.

Yingluck has proposed talks but the protesters have rejected them.

The incursion on the army’s turf was a bold act heavy with symbolism in a country that has experienced 18 successful or attempted military coups since the 1930s.

The most recent was in 2006, when the military ousted Yingluck’s brother, former Prime Minister Thaksin Shinawatra, who is living overseas to avoid a corruption conviction but is central to Thailand’s political conflict.

Protest organizers later declared that Sunday would be their “victory day,” and told followers to seize all state ministries, state telecommunications agencies and other state enterprises, police headquarters and the zoo.

The targets also include the prime minister’s offices. In 2008, anti-Thaksin demonstrators occupied those offices for three months to back their demands that his allies step down.

Senior security officials, including the interior minister and the national police chief, went on the government’s television station Friday night to ask people not to heed the protest call, calling the proposed actions illegal. Deputy Prime Minister Pracha Promnok said authorities will try to avoid using force in protecting government offices, and accused protest leader Suthep Thaugsuban of causing tremendous damage to the country.

For the past week, thousands of anti-government protesters have marched in Bangkok in a bid to unseat Yingluck, whom they accuse of serving as a proxy for her billionaire brother. Thaksin is adored by much of the country’s rural poor and despised by the educated elite and middle class who accuse him of widespread corruption and other offenses.

Leaders of the protests say their goal is not just to force Yingluck out of office but to rid the country of Thaksin’s influence in politics.

The demonstrations have raised fears of new political turmoil and instability in Thailand. A planned Bangkok rally today by Thaksin’s supporters has raised tensions further.

Protesters branched out to several spots on Friday, with another crowd staging a rally outside the headquarters of Yingluck’s ruling Pheu Thai party, where hundreds of riot police stood guard to prevent them from entering.

A separate crowd of more than 1,000 people marched through central Bangkok to the U.S. Embassy. Opposition lawmaker Korn Chatikavanij, a former finance minister, delivered a letter to an official there denouncing Yingluck’s leadership as illegitimate, in response to a statement from Washington that expressed concern about the protests.

Explaining how a crowd of unarmed civilians was able to break through the main gate into the army compound, Gen. Prayuth said: “The army did not want to use any force and we didn’t view the protesters as enemies or opponents. They are actually Thais who have different political opinions.” But he added, “In any case, security measures will be tightened from now on.”

Yingluck has been reluctant to use force against the opposition-led protesters for fear of escalating the crisis and sparking bloodshed.