JACKSON (AP) — A rare, heavy snowfall in Mississippi forced many schools and government offices to close Friday, and authorities warned of hazardous road conditions created by the weather.

Ariel Cohen, a meteorologist with the National Weather Service, said the winter storm system could drop as much as 4 to 8 inches across southern and central Mississippi and much of Louisiana on Friday. He said the road conditions are dangerous and people should avoid travel.

Troopers had worked about 20 wrecks, said Sgt. James Walker of the Mississippi Highway Patrol. No one had died, and most were fender-benders, he said.

‘‘People are just sliding off the road into ditches and they might need a wrecker,’’ he said.

Cohen said there were reports of numerous accidents caused by the icy roads and bridges.

The snowfall began Thursday night in the Delta and spread east and southward. By early morning Friday, the snowfall had intensified in much of central and south-central areas.

A winter storm warning was in effect for central and south Mississippi until 2 p.m. Friday.

Gov. Haley Barbour on Thursday ordered state offices south of U.S. 82 to close. The governor has declared a state of emergency and alerted the National Guard to be prepared to respond to situations created by the snow storm.

‘‘This is a time to be safety-minded and to check in on your elderly and housebound neighbors to make sure they have what they need to get through this winter storm,’’ Barbour said in a statement.

Announcements of school closings began on Thursday. Some colleges, including Alcorn State University in Lorman, Jackson State University and Hinds Community College in Raymond have closed their campuses.

The wintry mix drew residents outdoors as some had snowball fights in Hattiesburg and others built snowmen in Jackson.

Rafael Williams, 8, was walking in the snow through a Jackson neighborhood and posing for pictures with Brittany Armstrong, 22, and DeeDee Dunmore, 28.

‘‘I love it. It’s never been this way before since I’ve been alive,’’ the 8-year-old said.

Armstrong said ‘‘the snow makes everything beautiful.’’

Jeff Rent, a spokesman for the Mississippi Emergency Management Agency, said early Friday that Mem w &kadnGt been contacted by any counties for assistance, but there had been several calls about the accumulation.

The Mississippi Department of Transportation said it had received accumulation reports in Jefferson, Issaquena, Yazoo, Humphreys, Holmes, Lexington, Hinds, Sharkey, Warren, Scott, Leake, Neshoba, Newton, Forrest, Lamar, Perry, Greene, Jones, Wayne, Clarke, Copiah, Claiborne, Jasper and Lauderdale counties.

MDOT was sending snow plows from the northern part of the state to the south.

Cohen said significant snowfall rarely happens in Mississippi in February. He said in 1968, the Jackson airport reported 3.6 inches of accumulation over a three-day period. In 1901, there were four inches of accumulation, he said.