FERGUSON, Mo. — 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 it was unclear whether the panel was still at work or when it would render a decision.

Earlier in the day, a spokesman for St. Louis County Prosecutor Bob McCulloch told reporters that jurors were reviewing evidence as they weigh whether to indict officer Darren Wilson.

Five hours later, Ed Magee declined to say whether the panel was still meeting.

The time, date and place for a news conference announcing the decision has not been decided, Magee said.

Wilson, 28, reportedly told the grand jury that he feared for his life Aug. 9 as Brown, who was 6-foot-4 and nearly 300 pounds, came at him. Witnesses said Brown was trying to surrender and had his hands up.

The shooting of an unarmed 18-year-old black man by a white police officer led to protests, some of which turned violent. Demonstrations have continued for more than three months, though the number of protesters has dwindled and violence has become uncommon.

There were signs of rising tension.

Protesters were arrested Thursday outside Ferguson police headquarters for the second night in a row after around 40 demonstrators blocked South Florissant Road. One of the three arrested pushed an officer and was hit with pepper spray, St. Louis County Police spokesman Brian Schellman said.