Gaza's civil defence agency said 22 people, including at least six children, were killed in Israeli strikes in the Palestinian territory on Wednesday.
Agency spokesman Mahmud Bassal said one strike killed 10 members of the same family sheltering in the Al-Mawasi area west of Khan Yunis, while another on the Al-Shati camp near Gaza City left 10 dead and more than 30 wounded.
The victims in Al-Shati were from two families, he added.
Asked for comment, the Israeli military said it was looking into the reports.
"The explosion was massive, like an earthquake," said Zuhair Judeh, 40, who saw the Al-Shati air strike.
"The bodies and remains of the martyrs were scattered."
The bombings came as Israeli Prime Minister Benjamin Netanyahu met US President Donald Trump in Washington to discuss the ongoing campaign to defeat Hamas in Gaza.
"You can't predict when or why they'll bomb you," 36-year-old Abeer al-Sharbasi said after the Al-Shati strike.
"We have nothing left but to surrender ourselves to God."
Sobbing crowds of mourners gathered at Gaza City's Al-Shifa Hospital.
The director of the medical complex, Mohammad Abu Salmiya, told journalists on Wednesday that it would "be completely out of service due to the fuel shortage" within hours.
Israel's offensive and restrictions on supplies entering Gaza have taken a heavy toll on its medical system.
AFP footage from Al-Mawasi showed makeshift tents torn to shreds by the strike there, with a child's stuffed toy lying among the wreckage.
"We are extremely tired. Every day they say there is a ceasefire, but there are massacres," said displaced Palestinian Umm Ahmed.
In Khan Yunis, mourners gave a final embrace to loved ones whose bodies were laid out on the floor.
Bassal later reported two other people killed in separate strikes in central Gaza and in Gaza City.
Due to restrictions imposed on media in the Gaza Strip and difficulties accessing the area, AFP is unable to independently verify the death tolls and details shared by the parties involved.
Israel has killed at least 57,680 people in Gaza, also mostly civilians, according to the Hamas-run territory's health ministry. The UN considers the figures reliable.
The medical charity Doctors Without Borders (MSF) said on Wednesday that a recent mortality survey conducted among its staff and their families in Gaza corroborated figures provided by the territory's health ministry.
COMMENTS
Comments are moderated and generally will be posted if they are on-topic and not abusive.
For more information, please see our Comments FAQ