The United States voiced regret Monday that several people have been killed in clashes rocking Thailand and urged the opposition and beleaguered Prime Minister Yingluck Shinawatra to hold talks to end the political crisis.
"We are concerned about the continuing political tension in Thailand and we are following the situation closely," State Department spokeswoman Jen Psaki said.
"Peaceful protest and freedom of expression are important aspects of democracy... Violence and seizure of public or private property, however, are not acceptable means of resolving political differences."
US ambassador Kristie Kenney had spoken with Yingluck and with opposition leaders to "encourage restraint and peaceful dialogue," Psaki told reporters.
"We certainly deeply regret the loss of life in Bangkok due to politically motivated violence. We condemn violence as a means to achieve political objectives and urge all sides to exercise restraint and respect the rule of law," she added.
Yingluck Monday rejected the demands of demonstrators who have urged her to quit, as police issued an arrest warrant for "insurrection" against the protest leader.
Police used rubber bullets, tear gas and water cannon against rock-throwing demonstrators as they strengthened their defense of key government buildings, after weekend unrest in the capital left several dead and more than 100 wounded.
The protests, aimed at unseating the elected government and replacing it with a "people's council", are the latest outbreak of civil strife to rock the kingdom since royalist generals ousted Thaksin Shinawatra, Yingluck's brother, seven years ago.