The Israeli military on Monday announced the death of a soldier in fighting in the Gaza Strip, bringing the total number of troops killed since the October 7 Hamas attacks on Israel to 600.

The military announced the death of 20-year-old soldier Nadav Cohen, and updated its overall toll to 600 killed since the attacks that triggered the war.

Meanwhile, Israeli police said they had arrested the sister of Hamas leader Ismail Haniyeh as part of a terror probe in southern Israel.

Police told AFP that Sabah Abdel Salam Haniyeh, who is an Israeli citizen, was taken into custody in the town of Tel Sheva as part of an investigation also involving Israel's security agency Shin Bet.

A police spokesman, who confirmed it was Haniyeh's sister, said she is "suspected of having contact with Hamas operatives and identifying with the organisation, while inciting and supporting acts of terrorism in Israel".

Police said they found in the 57-year-old's house "documents, media, telephones, other findings and evidence linking her to the commission of serious security offences against the State of Israel".

Ismail Haniyeh, who lives in Doha, is the head of Hamas's political bureau.