BANGKOK, Thailand (AP) -- Thailand's prime minister said Friday that political tensions in Bangkok will likely ease after the arrests of leaders of an anti-government protest that turned violent and resulted in hundreds of injuries.

Nine suspects from the United Front of Democracy Against Dictatorship were detained Thursday after they appeared in court to hear police allegations against them, including illegal assembly, causing a public disturbance, damaging state property, and obstructing the work of, and injuring, officials.

The protesters called their detention too harsh a punishment, but authorities disagreed.

"I believe that the political situation will be calmer now," Prime Minister Surayud Chulanont told reporters. "When the case goes to court, we can explain to people that what was done was not an abuse (of power)."

Most of the nine are leading members of ex-Prime Minister Thaksin Shinawatra's now disbanded Thai Rak Thai Party. Thaksin was ousted in September in a bloodless coup.

The Thai military ousted Thaksin on Sept. 19, 2006 while he was abroad, accusing him of corruption and abuse of power. It installed an interim government and a council to draft a new constitution, which will be submitted to a national referendum on Aug. 19. A general election is supposed to be held in December.

"It's close to the time for the referendum and we should gear toward that ... It is not a good thing to stage a violent protest," said Surayud. "The government is willing to listen to criticism, if they are reasonable criticisms."

Bangkok police chief Lt. Gen. Adisorn Nontree said bail would not be granted because "the suspects would cause further trouble and instigate more violence if they are set free."

Bangkok Criminal Court Thursday allowed police to hold the suspects for two days for investigation. Then they will be transferred to the custody of the court for 10 more days. Suspects can be held for up to 48 days without being formally charged, but police must apply to the courts to have detentions extended every 12 days.

Violence broke out Sunday at a rally by several thousand people outside the home of former Prime Minister Prem Tinsulanonda -- the chief adviser to revered King Bhumibol Adulyadej. The protesters accuse Prem of instigating the coup against Thaksin, and have called for him to resign his post.

About 200 police officers and 70 protesters were hurt, most with minor injuries. Some officials have blamed Sunday's violence on Thaksin who has been accused of financing the anti-coup movement.

Thaksin denies such allegations, and earlier this week issued a call for peace and reconciliation.

Prasong Soonsiri, chief of the Constitution Drafting Committee,said Thursday those organizing the recent protests against the military-backed government want to cause bloody riots that will receive publicity overseas to give the impression that Thailand's new leadership is brutal and authoritarian.