Al-Jalaa hospital said on Facebook it had received the bodies of four men in their 70s and one aged 65 killed yesterday evening in "indiscriminate shelling of Beirut Street" in central Benghazi.
Seventeen other people were brought to the hospital suffering from various wounds, it added.
Benghazi has been reeling from more than a year of near-daily clashes between pro-government forces and armed groups, including Islamists, battling for control of the eastern city.
Libya was plunged into chaos after the overthrow of Moamer Kadhafi's regime in 2011, with rival militias fighting for their own territorial and financial interests in the oil-rich country.