Thailand took a tough position against anti-government protesters yesterday, rejecting demands for U.N.-supervised talks and calling on their leaders to surrender on the fourth day of deadly clashes with troops.


The government doused hopes of a compromise to end fighting that has killed at least 31 people, all civilians, and wounded 230, transforming one of Asia’s most dynamic cities into a battleground and raising the risk of a broader conflict.


“We cannot retreat now,” Prime Minister Abhisit Vejjajiva said in a televised statement, encapsulating the government’s all-or-nothing campaign to end two months of protests seeking to topple his fragile, ruling six-party coalition.


The mostly rural and urban poor protesters, supporters of ousted premier Thaksin Shinawatra, accuse the government of colluding with the royalist elite and meddling with the judiciary to bring down two Thaksin-allied governments.


Analysts and diplomats said the military appears to have underestimated the resolve of thousands of “Red Shirt” protesters barricaded in a 1.2-square-mile district of luxury hotels and shopping malls for six weeks.