A high-level Qatari delegation has been discussing the proposals with Israeli officials in unannounced meetings held in Norway since December 16, the source told Xinhua news agency on Sunday, noting that the talks were "exploratory".

"In coordination with Egypt, Qatar is seeking to revive the swap deal between Israel and Hamas in a bid to reach new understandings for a humanitarian ceasefire in Gaza," the source said.

The discussions have touched on releasing the remaining Israeli hostages taken by Hamas in exchange for several days of humanitarian truce in Gaza as well as the release of Palestinian prisoners from Israel, the source added.

Qatar is seeking to release three senior Israeli officers in exchange for the release of several Palestinian prisoners who are serving life imprisonment in Israeli prisons, according to the source.

The new Qatari diplomatic efforts came after three Israeli soldiers, who were captured by Hamas, were accidently killed by the Israeli army in Gaza.

The unprecedented incident sparked controversy among the Israelis and led to the intensification of pressure on the Israeli government to release the remaining 129 hostages.

Meanwhile, Hamas, the de facto ruler of the war-torn enclave, declined to involve in any new negotiations with Israel unless the latter ends its offensive on Gaza.

In a statement sent to Xinhua, the militant group said that "we informed our position to all mediators that we will not open our minds to any proposals unless the Israeli aggression stopped in Gaza".

Qatar and Egypt had previously mediated a seven-day humanitarian truce late last month as Hamas released about 86 Israeli hostages and 24 foreign hostages from Gaza.

This latest development comes as Israel has stepped up bombardments on the Gaza Strip.

The Israel Defense Forces (IDF) spokesperson unit reportedthat heavy fighting took place across Gaza, with Israeli forces striking more than 200 locations on December 16.

Israeli forces raided a building near a UN Relief Works Agency school, claiming to have found machines for the production of rocket parts, and three tunnel shafts nearby.

The IDF said it has uncovered the largest underground Hamas tunnel system in Gaza so far.

The system splits into branches of tunnels, spans over more than 4 km and reaches 400 metres from the Erez crossing, a passageway between Gaza and Israel.

Since the war erupted on October 7, at 18,787 people have died in the Gaza Strip, about 70 per cent of those killed are said to be women and children.

Israel has reported more than 1,200 fatalities, including foreign nationals,