The report said it looked into seven Israeli strikes that had killed Palestinians in areas of southern Gaza designated as safe zones by Israel.
These strikes occurred from January to April, the report noted.
The report said that on December 18, Israeli armed forces dropped leaflets in Gaza that identified the Tal Al Sultan, Al Zuhur, and Al Shaboura neighborhoods as safe and told Gaza residents to seek shelter there.
However, NBC News said its investigation found that all three locations have been hit by Israeli airstrikes since then.
NBC News said they were told by the Israel Defense Forces that they continue to consider these designated areas as safe zones.
Israel's operation in Gaza has resulted in the death of more than 34,000 Palestinians and the wounding of over 77,000 Palestinians since October.