
"We, the 40 senators, call on the UNHCHR to take appropriate measures to prevent and stop human-rights violations in Thailand," the statement said.
The senators voiced concern that there was widespread discontent resulting from the violent crackdown on protesters.
The government, which is suspected of being a proxy of former prime minister Thaksin Shinawatra, ordered the use of tear gas to disperse peaceful crowds congregating in front of Parliament, the letter said.
The sole reason cited by the government in justifying the crackdown was the need for Prime Minister Somchai Wongsawat to deliver his policy statement to Parliament, it added.
During the reading of the policy statement, protests continued on the grounds that the session lacked legitimacy and was boycotted by a number of senators and the opposition MPs. Crowd-control operations were carried out with cruelty throughout the day, resulting in more than 400 casualties, including two deaths, the senators said.
The senators tried in vain to prevent the violence. A statement was issued on October 6 calling on the government to postpone the parliamentary session and avoid the crackdown, the letter said.
After the government ordered the crowd dispersal, the senators protested by boycotting the session to avoid lending legitimacy to the government and the policy statement while people were sustaining serious injuries in front of Parliament.
Senator Prasarn Maruekkhapitak yesterday said the Senate would launch an investigation into the violent crackdown.
Former senator Prathin Santiprapob has been approached to lead the probe, he said. The investigative report should be complete within two to four weeks.