By Daniel Wallis and Ellen WulfhorstFERGUSON, Mo. (Reuters) - A St. Louis-area grand jury was expected on Monday to resume deliberations over whether to bring charges against a white policeman who shot and killed a black teenager in a case that has triggered months of demonstrations and set the city on edge.With no one knowing how long that process might yet run, residents are anxious and shop fronts are boarded up in fear of unrest, while students in one school district began an extended early Thanksgiving break.The Aug. 9 killing in Ferguson, Missouri, of 18-year-old Michael Brown by officer Darren Wilson was the latest flashpoint in often-troubled U.S. race relations.Lawyers for Brown's family have said the teen was trying to surrender when he was shot, while Wilson's supporters say he feared for his life and only opened fire in self-defense.More than 100 demonstrators marched in the rain in another St. Louis suburb late on Sunday, waving placards reading "Where Do You Stand'" and "Black Lives Matter".The protesters blocked traffic at an intersection for more than four minutes in a symbolic gesture to the more than four hours that Brown's body lay in the street after he was shot.Some media reports suggested a grand jury decision was coming this past weekend, fueled by the erection of barriers around the court where the panel meets and word from prosecutors that they would hold a news conference to make the announcement.But the date, time and location of that event are yet to be determined and the St. Louis County prosecutors' office, which has repeatedly said it cannot comment on grand jury proceedings, did not respond to requests for any updates on Sunday.The Wall Street Journal, citing an unidentified county official, said the 12-member panel had not reached a decision and would reconvene behind closed doors on Monday. Reuters could not independently verify the report.Missouri Governor Jay Nixon has declared a state of emergency in anticipation of the grand jury's verdict and called in the National Guard. One school district canceled classes on Monday and Tuesday, although others plan to stay open.Ferguson, a predominantly black suburb of 21,000 people, has seen nightly, peaceful protests since last week by demonstrators demanding Wilson be indicted. Police have arrested a handful, almost all for failure to disperse after blocking traffic.Brown's parents have urged sympathizers to remain peaceful, whatever the outcome.Some protesters, who complain they are painted as violent by the mass media, were angered by a CNN report on Sunday that said two of its journalists, as well anchors from other major networks, had held off-the-record meetings with Wilson in the hope of securing his first broadcast interview.One activist said the only interview of Wilson he wanted to see would be conducted by Oprah Winfrey, from prison.(Editing by Chris Michaud and Paul Tait)Join the conversation about this story Click here to read full news..