Medics in Gaza said 45 people in total were killed in Israeli airstrikes across the enclave on Saturday.
At least 15 Palestinians were killed and 50 wounded by airstrikes in the Gaza City district of Sabra in the northern Gaza Strip on Saturday, local health authorities said.
Six people were killed in a shooting near a US-backed aid distribution centre.
More than one missile landed in the area. The target seemed to have been a multi-floor residential building, but the explosion damaged several other houses nearby, according to witnesses and media.
The shooting deaths were the latest reported near the aid centre run by the Gaza Humanitarian Fund (GHF) in the southern district of Rafah and came after it resumed distributions following a brief suspension in the wake of similar deaths earlier this week.
The Israeli military has retrieved the body of a Thai hostage who had been held in Gaza since Hamas' October 7, 2023 attack, Defence Minister Israel Katz said on Saturday.
Nattapong Pinta's body was held by a Palestinian group called the Mujahedeen Brigades, and was recovered from the area of Rafah in southern Gaza, Katz said. His family in Thailand has been notified.
Pinta, an agricultural worker, was abducted from Kibbutz Nir Oz, a small Israeli community near the Gaza border where a quarter of the population was killed or taken hostage during the Hamas attack that triggered the devastating war in Gaza.
An aid boat with 12 activists on board, including Swedish climate campaigner Greta Thunberg, was meanwhile nearing Gaza in a bid to highlight the plight of Palestinians in the face of an Israeli blockade that has only been partially eased.
Civil defence spokesman Mahmud Bassal told AFP that at around 7am, "six people were killed and several others wounded by the forces of the Israeli occupation near the Al-Alam roundabout".
Gazans have gathered at the roundabout almost daily since late May to collect humanitarian aid from the GHF aid centre about one kilometre away.
AFP is unable to independently verify the tolls compiled by the civil defence agency or the circumstances of the deaths it reports.
The Israeli military told AFP that troops had fired "warning shots" at individuals that it said were "advancing in a way that endangered the troops".
Samir Abu Hadid, who was there early Saturday, told AFP that thousands of people had gathered near the roundabout.
"As soon as some people tried to advance towards the aid centre, the Israeli occupation forces opened fire from armoured vehicles stationed near the centre, firing into the air and then at civilians," Abu Hadid said.
The GHF, officially a private effort with opaque funding, began operations in late May as Israel partially eased a more than two-month aid blockade on the territory.
UN agencies and major aid groups have declined to work with it, citing concerns it serves Israeli military goals.
Israel has come under increasing international criticism over the dire humanitarian situation in the Palestinian territory, where the United Nations warned in May that the entire population was at risk of famine.
The aid boat Madleen, organised by an international activist coalition, was sailing towards Gaza on Saturday, aiming to breach Israel's naval blockade and deliver aid to the territory, organisers said.
"We are now sailing off the Egyptian coast," German human rights activist Yasemin Acar told AFP. "We are all good," she added.
In a statement from London, the International Committee for Breaking the Siege of Gaza -- a member organisation of the flotilla coalition -- said the ship had entered Egyptian waters.
The group said it remains in contact with international legal and human rights bodies to ensure the safety of those on board, warning that any interception would constitute "a blatant violation of international humanitarian law".
The Palestinian territory was under Israeli naval blockade even before the October 7, 2023 attack by Hamas that sparked the Gaza war and the Israeli military has made clear it intends to enforce the blockade.
"For this case as well, we are prepared," army spokesman Brigadier General Effie Defrin said on Tuesday, when asked about the Freedom Flotilla vessel.
"We have gained experience in recent years, and we will act accordingly."
A 2010 commando raid on the Turkish ship Mavi Marmara, which was part of a similar attempt to breach Israel's naval blockade, left 10 civilians dead.
The Israeli military has stepped up its operations in Gaza in recent weeks.
In a special operation in the Rafah area on Friday, Israeli forces retrieved the body of Thai hostage Nattapong Pinta, Defence Minister Israel Katz said.
The military said Nattapong's family and Thai officials had been notified of the operation to recover his body.
Thai Foreign Ministry spokesman Nikorndej Balankura said the country was "deeply saddened" by his death.

Palestinians extinguish a fire at the site of an Israeli strike on a house, in Gaza City, on Saturday. REUTERS

Palestinians inspect the damage at the site of an Israeli strike on a house, in Gaza City, on Saturday. REUTERS

Palestinians inspect the damage at the site of an Israeli strike on a house, in Gaza City, on Saturday. REUTERS

Palestinians search for casualties at the site of an Israeli strike on a house, in Gaza City, on Saturday. REUTERS

Palestinians gather at the site of an Israeli strike on a house, in Gaza City, on Saturday. REUTERS