Anti-government protesters said Sunday they would not negotiate an end to violence in the Thai capital after savage clashes between activists and soldiers that killed at least 18 people and injured hundreds.Thousands of "Red Shirt" protesters swarmed back into an area that had briefly been taken by government forces Saturday night. Bullet casings, rocks and pools of blood littered the streets as protesters showed off a pile of weapons captured from the troops, including rifles and heavy caliber machine-gun rounds."There is no more negotiation. Red Shirts will never negotiate with murderers," a key protest leader, Jatuporn Prompan, announced from a makeshift stage. Thai television showed Red Shirts parading some soldiers they said were captured by the protesters. It wasn't clear how many soldiers they held, or what their status was on Sunday morning. The government did not disclose how many protesters had been detained.Arrest warrants previously were issued for 27 Red Shirt leaders, but none is known to be in custody.Editorials in Bangkok newspapers Sunday called for urgent talks between the government and so-called "Red Shirts," noting some protest leaders were ready for negotiations. The violence erupted after security forces tried to push out demonstrators who have camped in parts of the capital for a month and staged disruptive protests demanding that Prime Minister Abhisit Vejjajiva dissolve Parliament and call new elections. The demonstrations are part of a long-running battle between the mostly poor and rural supporters of former Prime Minister Thaksin Shinawatra, and the ruling elite they say orchestrated the 2006 military coup that removed him from power amid corruption allegations.The protesters, called "Red Shirts" for their garb, see the Oxford-educated Abhisit as a symbol of an elite impervious to the plight of Thailand's poor and claim he took office illegitimately in December 2008 after the military pressured Parliament to vote for him.Saturday's violence and failure to dislodge the protesters are likely to make it harder to end the political deadlock. Previously, both sides had exercised considerable restraint. Abhisit "failed miserably," said Michael Nelson, a German scholar of Southeast Asian studies working in Bangkok.Tanet Charoengmuang, a political scientist at Chiang Mai University sympathetic to the Red Shirt's cause, said he expects the fighting will resume because the protesters are unafraid and the government refused to listen to them.Abhisit went on national television shortly before midnight to pay condolences to the families of victims and indirectly assert that he would not bow to the protesters' demands. At least 825 people were injured, according to the Erawan emergency center. The deaths included Japanese cameraman Hiro Muramoto, who worked for Thomson Reuters. In a statement, Reuters said he was shot in the chest and the circumstances of his death were under review. Most of the fighting took place around Democracy Monument, but spread to the Khao San Road area, a favorite of foreign backpackers. Soldiers made repeated charges to clear the Red Shirts, while some tourists watched. Two protesters and a Buddhist monk with them were badly beaten by soldiers and taken away by ambulance. A Japanese tourist who was wearing a red shirt was also clubbed by soldiers until bystanders rescued him. Thai television showed Red Shirts parading some soldiers they said were captured by the protesters.