The morning after the government issued the 60-day emergency decree, an unidentified gunman opened fire with an AK47 assault rifle on Kwanchai Praipana, a leader of Thailand's pro-government "red shirt" movement and a popular radio DJ, as he sat outside his home reading a newspaper.
The attack in Udon Thani, about 450 km (280 miles) northeast of Bangkok, is the most significant violence outside the Thai capital in nearly three months of anti-government protests and illustrates the risk that the turbulence plaguing Bangkok could spread to other areas of Thailand.
Several governments have warned their nationals to avoid protest areas in Bangkok, among the world's most visited cities. China called on Thailand to "restore stability and order as soon as possible" through talks.
Police said they believed the shooting in Udon Thani was politically motivated.
Kwanchai leads thousands of red-shirted supporters in Udon Thani, a province of about 1.6 million people in the heart of the country's mostly poor "Isaan" region, a rugged northeastern plateau that is home to a third of the country's population and has staunchly backed Yingluck.
Just days earlier, he had warned of a nationwide "fight" if the military launched a coup.
"From the way the assailants fired, they obviously didn't want him to live," his wife, Arporn Sarakham, told Reuters. Police said they had found 39 bullet cases at the house. The gunman and a driver fled in a pickup truck.
On Tuesday, he told Reuters that if the military attempted a coup: "I can assure you, on behalf of the 20 provinces in the northeast, that we will fight. The country will be set alight if the soldiers come out."
FEARS OF ELECTION DAY VIOLENCE
So far the military, which has been involved in 18 actual or attempted coups in the past 81 years, has kept out of the fray. The police are charged with imposing the state of emergency, under orders from Yingluck to treat protesters against her government with patience.
Paul Chambers, director of research at the Institute of South East Asian Affairs in Chiang Mai, said the emergency decree was designed largely to give Yingluck legal protection if there is violence and the police step in.
It gives security agencies powers to detain suspects, impose a curfew and limit gatherings.
Nine people have died and dozens have been wounded in violence, including two grenade attacks in the capital over the weekend, since protesters took to the streets in November to demand Yingluck step down and a "people's council" be set up to bring sweeping reforms to Southeast Asia's second-biggest economy.
The protests are the latest eruption in a political conflict that has gripped the country for eight years. It pits the middle class of Bangkok and royalist establishment against the mainly poorer supporters of Yingluck and her brother, ex-premier Thaksin Shinawatra, toppled by the military in 2006.
Yingluck called a snap election for Feb. 2 in the hope of defusing the protests.
The Election Commission is worried it will fan the violence and says the protests have prevented some candidates from registering, meaning there will not be a quorum to open parliament. It is asking the Constitutional Court to rule on whether it can delay the vote.
"If it happens on Feb. 2, there will not be enough new MPs for a new government to be formed anyway. Then Thailand would move to a period of growing limbo where the anti-Thaksin judiciary would decide on whether to void the election or not," Chambers said.
Protest leader Suthep Thaugsuban has rejected the election outright. He accuses Thaksin of corruption and nepotism and wants to change the electoral system to eradicate the influence of Thaksin, who lives in exile in Dubai to avoid a jail term handed down in 2008 for abuse of power.
His protest group issued a statement calling the emergency decree a sign of the government's growing desperation.
Suthep, when he was a deputy prime minister, sent in troops to end mass protests by pro-Thaksin supporters in 2010. More than 90 people died in that unrest.
The crisis has hurt tourism and business confidence. But the central bank, in unexpectedly positive comments, said it thought the impact would only be short-term.
Adding to Yingluck's problems, farmers, who are part of her core constituency, have threatened to join the protest if they do not get paid for the rice they have sold to the government under a controversial intervention scheme.
Her government guaranteed them an above-market price for their rice but the scheme has run into funding difficulties.
The government has sold a bond and is seeking loans to tide it over, but the Election Commission, which has to approve such action by the caretaker government, has declined to give its support.