A Hamas member was killed on Monday when a tunnel collapsed in the Gaza Strip, the group's military wing said in a statement.
The Ezzedine al-Qassam Brigades named the man as Amir Jaber Abu Taimeh and said the accident occurred in the town of Khan Yunes. It gave no further details.
Over the past few months at least 16 militants have died in tunnel accidents in the strip.
Another al-Qassam Brigades member was killed in a collapse near Al-Maghazi in the central Gaza Strip on Saturday.
Israel accuses Gaza militants of building tunnels for use in attacks against the Jewish state, and destroyed several during the devastating 2014 war with Hamas.
The Islamist movement, which controls the coastal enclave, and other militant groups such as Islamic Jihad have a network of tunnels in the Israeli-blockaded territory, both for smuggling and militant purposes.
Egypt, which shares a border with Gaza, has also destroyed tunnels Palestinians use to smuggle commercial goods, cash, people and allegedly weapons.