FERGUSON • Leaders of the Michael Brown protests gathered Monday afternoon to cancel plans for blocking highways, but a few impromptu closings took place about three hours later.

A group of protesters entered the westbound lanes of Interstate 270 near West Florissant Avenue and blocked traffic. The Missouri Highway Patrol said the protesters left the roadway a short time later.

St. Louis police received numerous telephone reports of attempts to block traffic at three places on Interstate 70 in the city and three others at traffic-light intersections. But responding officers couldn’t find anything when they arrived, a spokeswoman said.

All of the reports took place about 4:30 p.m., which had been part of the original plan to close stretches of highway in the continuing protests over the fatal shooting of Brown, 18, by a Ferguson police officer on Aug. 9.

Shortly after 1 p.m. Monday, protest leaders gathered in front of the Ferguson police station and announced they were canceling plans for an action at the request of Brown’s father, Michael Brown Sr.