A torn rubber dinghy that normally carries 120 people was found nearby.
The Red Crescent's spokesman Mohammed al-Misrati told The Associated Press that the bodies were found Monday morning.
The Red Crescent posted photographs on its Twitter account showing dozens of body bags along the shore.
Libyan coast guard spokesman Ayoub Gassim said over 500 migrants were rescued at sea on Friday and Saturday off the shore of Sebratha, a city to the west of Zawiya. "Libya is not a safe place and blocking people in the country or returning them to Libya makes a mockery of the EU's so-called fundamental values of human dignity and rule of law", said Médecins Sans Frontières, which works in camps there. There have been many cases of refugees and migrants being tortured, forced into labour and raped whilst being held in the country.
A record 181,000 migrants reached Italy over the Mediterranean past year, majority leaving from Libya where people smugglers operate with impunity.
January 2017 saw 288 migrants perish en route to Europe, the highest monthly toll seen since the 2011 uprising that drove Libya into chaos and turned the country into a death trap for the many sub-Saharan Africans seeking to escape conflict, starvation or poverty. That compares to 2,869 deaths in 2015, and 3,161 in 2014.
Mourinho's chance for revenge over Chelsea
Manchester United have announced their starting eleven and substitutes for this afternoon's FA Cup tie away at Blackburn Rovers. He continued: "We know if we play to our best and Manchester United play to their best then, ordinarily, they will win.
There is little sign of the surge is abating, even during wintertime.
Though summer is usually the peak of migrant crossings, winter has still seen a few desperate escapes with 228 recorded deaths last month alone.
More than 180,000 people made the crossing past year, an increase of 17 percent from 2015.
Misrati said local authorities would take the bodies to a cemetery allocated for unidentified persons in Tripoli.
Sabratha, an important archaeological site and a launch point for migrants trying to reach Europe, was briefly seized by the Islamic State in 2016, according to media reports.
The post-Gaddafi civil turmoil engulfing Libya has seen the growth of human trafficking gangs, preying on migrants, majority from sub-Saharan African countries, seeking a better life in Europe.
Libya was plunged into turmoil by the 2011 uprising that toppled and killed longtime dictator Moammar Gadhafi, and has since emerged as a popular, if extremely risky, route to Europe for those fleeing poverty and civil war elsewhere in Africa.