Israel announced the closure of its Gaza border crossings in response to daily rocket fire from the enclave over the past week after US President Donald Trump's recognition of Jerusalem as Israel's capital stoked Palestinian anger.
The handover signalled that Hamas remained committed to a deal that would eventually see it give up full control of the Gaza Strip and bring an end to a 10-year rift with rivals Fatah.
A source for the Islamic Jihad group said Arafat Abu Marshould, head of the faction's armed wing in central Gaza, was killed along with a senior associate and two other gunmen.
Hamas agreed to hand over power to a unity government last month and Rami Hamdallah's visit, the first since 2015, saw his ministers take control of ministries in Gaza.
A suicide bomber killed a Hamas guard in southern Gaza on Thursday, in a rare Islamist attack against the Palestinian group that has run the impoverished enclave for a decade.
The Palestinian Authority has dramatically reduced financial support for Gazans seeking medical care outside the blockaded Gaza Strip, WHO figures showed on Wednesday.