Damage survey results so far indicate that it was one tornado that tracked from near Tallulah, LA across the Mississippi River through Issaquena County, Mississippi before entering Yazoo County and devastating Yazoo City. The tornado is ranked an EF4 and the path length was at least 97 miles (VERY rare). At least 10 confirmed deaths from this outbreak.
http://www.srh.noaa.gov/jan/?n=2010_04_24_tor_overview
The outbreak was forecast well in advance by the Jackson NWS office, which had issued several very ominous, strongly worded forecasts over the previous few days.