Protests go on as officer suspended after Facebook rant

Michael Brown.

A police officer in Missouri was suspended after he voiced his contempt via Facebook for protesters condemning the fatal shooting of a black teenager by a white police officer.

Some 50 demonstrators returned to the streets of the St Louis suburb of Ferguson at sunset on Friday, local time, to demand justice for the August 9 death of 18-year-old Michael Brown, whose funeral is set for tomorrow.

Police kept a low profile, in sharp contrast to previous nights when they fired tear gas and rubber bullets to disperse protesters near where Brown was fatally shot at least six times in broad daylight.

The police department in suburban Glendale said on Friday it had suspended an officer who expressed contempt for the Ferguson protesters on Facebook.

Matthew Pappert was the latest police officer from the St Louis area in three days to be suspended for questionable conduct amid the protests.

"I'm sick of these protesters. You are a burden on society and a blight on the community," wrote Pappert in one of at least five posts that has gone up since Sunday.

"These protesters should have been put down like a rabid dog the first night," he added.

In a reference to the Boston Marathon bombing, he also wrote: "Where is a Muslim with a backpack when you need them."

The Glendale Police Department said it suspended Pappert upon learning about the posts on Friday.

It also cancelled a neighbourhood block party for fear it might be disrupted by protesters.

"The matter is being taken very seriously and a thorough internal investigation will be conducted to determine why the posts were made," it said.

It stressed that the opinions in Pappert's posts were "absolutely" not shared by the Glendale police or city government.

On Wednesday, a police lieutenant from another St Louis suburb, St Ann, was suspended after he pointed a semi-automatic assault rifle at Ferguson protesters and, in vulgar language, threatened to kill them. Within hours, two videos of the officer's conduct went viral on YouTube, prompting the American Civil Liberties Union to demand he be removed from duty.

Meanwhile, some residents and officials trying to maintain peace worry what will happen if the grand jury now considering the case doesn't return a charge against the officer who shot Brown.

Senator Claire McCaskill's office said the Department of Justice hasn't given a timeline for the federal investigation, which centres on whether a civil rights violation occurred when officer Darren Wilson fatally shot the unarmed youth.

- AAP