A Palestinian militant from Islamic Hamas movement was killed Tuesday when a tunnel under Gaza's southern border with Egypt collapsed.

Hamas said that the 23-year-old member was inside the smuggling tunnel, but refused to give details what kind of work he was doing.

The tunnels are often used to bring in materials that Israel prevents from entering Gaza through commercial crossings, including construction materials and fuel.

Before Israel eased its Gaza blockade in June 2010, the tunnels had been the key lifeline of the 1.5 million inhabitants of the coastal enclave.

Israel often claims that the Palestinian militant groups smuggled weapons to Gaza with tunnel.