The Israeli construction industry has been at the center of several recent battles between the Israeli military and Hamas militants.
On Saturday, the Israeli forces announced that they had killed four militants in the vicinity of Rafah and that they were carrying out a military operation.
But the Palestinian Authority said that Israeli forces killed two Palestinian men on Sunday who had been working for the Hamas-affiliated group known as Ansar Bayt al-Maqdis.
Israeli officials have not released the identities of the two men killed in Rafah, and neither the Israeli army nor Hamas has claimed responsibility.
Israel also announced that it had killed two Hamas operatives in the Gaza Strip, and that it would release the identities and location of the dead militants.
Hamas claimed that Israeli warplanes targeted the headquarters of the Ansar al-Hayat, an organization it runs in Gaza, and killed four members of the organization, including two Hamas members.
In a statement, the Palestinian group said that the group was planning an attack on the headquarters.
It added that it was “preparing to launch a massive attack on Israel’s army and civilians” as a result of the attack.
Hospital staff told Al Jazeera that a number of Palestinians were injured and killed during the Israeli airstrikes.
Hospitals in Gaza City were reportedly hit with up to 10 strikes in the past 24 hours, the UN World Food Program said on Sunday, raising the death toll in the country to more than 1,300.
The Gaza Strip is controlled by Hamas, which rules the strip from Gaza City.
Harmony between Israel and Hamas is a common theme in Gaza politics.
The militant group has waged a decades-long insurgency against Israel, which has long refused to recognise the Palestinian state.