"443 people are dead and 2,110 others wounded due to violence in Tripoli, Libya," WHO tweeted.
"As the crisis continues and the number of displaced people approaches 60,000, WHO is working to coordinate ongoing health services for them," WHO added.
The east-based army, led by Khalifa Haftar, has been leading a military campaign since early April to take over Tripoli, where the UN-backed government is based.
Libya has been struggling to undergo a transitional period amid chaos since the fall of former leader Muammar Gaddafi in 2011.