Washington, May 28 (IANS/RIA Novosti) The US has urged the Georgian authorities to launch an investigation into this week's police crackdown on protesters, when several people were killed.

"As we've said elsewhere, we believe that the rights, peacefully express the aspirations of the citizens of Georgia, as in any country, should be respected. And we would call on a government investigation into the incidents of the last several days, which I believe - in which several people were killed," Mark Toner, a deputy spokesman for the US Department of State, told a daily press briefing.

Riot police used water cannons, rubber bullets and teargas to disperse opposition activists who gathered late on Wednesday night on the city's main street in an attempt to prevent an Independence Day military parade. They also sought to block the rostrum from which the president was expected to deliver a speech.

The opposition rally was sanctioned by the Tbilisi authorities to take place between May 21-May 25, but the protesters refused to leave the streets after the deadline.

Georgian President Mikheil Saakashvili said Thursday that outside forces seeking revenge were behind the protests.

The Georgian Interior Ministry said two people, one a former and the other a serving police officer, were killed after being run over by a motorized convoy of opposition leaders fleeing the scene. A total of 37 people, including eight police officers, remain hospitalised.

Ninety demonstrators were detained during the rally, with most put under two-month administrative arrests, a representative of the Georgian Interior Ministry said.

Several criminal cases have also been initiated over the unrest.