Time to rumble.

(Reuters) – Prosecutors are preparing a news conference to announce the decision of the grand jury weighing whether to bring charges against a white police officer who shot dead an unarmed black teenager in Ferguson, Missouri, officials said on Friday.

The grand jury was still in session on Friday and no date or time for the decision announcement was known, the St. Louis County Prosecuting Attorney’s Office said. Officials have said a decision by the grand jury is expected by the end of the month.

U.S. Attorney General Eric Holder urged police to show restraint in dealing with any protests that may follow the grand jury’s decision on whether to indict the officer, Darren Wilson, in the Aug. 9 shooting of 18-year-old Michael Brown.

Update:

FERGUSON, Mo. (AP) — Activists, authorities and the family of Michael Brown called for calm Friday as a grand jury drew closer to an announcement in the Ferguson police shooting. But a spokesman for St. Louis County’s top prosecutor said the panel is still in session.

There was no indication when the grand jury would render a decision on whether to indict Ferguson officer Darren Wilson in the death of Brown, who was 18 and unarmed when he was killed.

Ed Magee, a spokesman for county Prosecutor Bob McCulloch, said Friday in an email to reporters that the grand jury is still reviewing the case. The time, date and place for a news conference announcing the decision has not been decided, he wrote.