"There was a brief and temporary suspension of aid, but I am very pleased to say, that following an assessment of the situation, UNRWA [the UN agency for Palestinian refugees] has resumed all its services," said John Ging, UNRWA's Gaza chief.
Ging said his organisation had food supplies in its Gaza warehouses that could last for 10 days. However, border crossings into the Strip remained closed, affecting supplies of perishable items such as milk.
"The next challenge is to get aid into Gaza. The crossings must open," Ging said.
Aid workers in Gaza said that many food stuffs in shops are running out, largely because uncertainty has driven people to stock up on basic items.
Limited gas supply
In addition, Gaza's gas supply, which comes from Israel, has been stopped; although it is likely supplies to the Gaza power station will continue. The Israeli government and gas supply company Dor Alon have both held each other responsible for the decision. Observers say the move could lead to severe shortages of petrol and cooking gas within days.
Benyamin ben Eliezer, the Israeli minister of infrastructure, told local radio: "We must end all aid and help to Gaza. I am ending it all until I understand what is going on there."
Hospitals struggling to cope
More than 100 people, many civilians, have been killed in fighting between Hamas and Fatah militants. Hospitals are struggling to cope with the wounded.
"The hospital is overcrowded with the injured. We have stopped normal activities and we are only doing emergency work," Dr Jouma al-Saka, from Gaza's main Shifa Hospital, told IRIN.
Last week's infighting ended after Hamas gained control over the entire Gaza Strip by taking over positions held by Palestinian Authority security forces affiliated with the rival Fatah movement and its head, President Mahmoud Abbas.
Shlomo Dror, a spokesman for the Israeli Ministry of Defence's humanitarian coordination section, blamed Hamas for the border closures.
"As of right now, the Palestinians closed all the crossings, so we can't bring in any aid. We will have to be creative," Dror said.
West Bank violence
Concerns remain that violence in Gaza could cause instability in the West Bank, where the Fatah movement remains strong. Over the weekend its militias conducted what are being described as 'power shows' - masked gunmen patrolling the streets of large cities issuing anti-Hamas statements.
On 16 June, Fatah militants stormed the Hamas-controlled Palestinian parliament building in Ramallah and attempted to seize the Palestinian Legislative Council's second deputy speaker.
Other Fatah supporters in the West Bank ransacked the Hamas-led Ministry of Education and took over the Hamas-controlled legislative council in Nablus, in northern West Bank.
Also on 16 June, militants presumed to be affiliated to Fatah, stole several tons of food from a World Food Programme (WFP) warehouse in Nablus and looted its office.
"I am extremely concerned by this unprecedented attack," said Arnold Vercken from the WFP. "This food is intended for chronically poor families who have very little means of surviving without it... Our continued work relies on security guarantees for our staff and partners on the ground."
A WFP statement warned that its "humanitarian mission is becoming increasingly challenging amidst the current security environment".
However, while some violence has spread to cities such as Nablus and Ramallah, the security situation is currently stable.
"The truth is, we really just don't know what the situation will be like, here or in Gaza. We are preparing for everything, but we don't know exactly for what," said a Palestinian aid worker in the West Bank, who asked not to be named.