Israel launched a war on the Hamas-ruled Gaza territory in December and January last year.

More than 1,400 Palestinians were killed in the war.

Dozens of tunnels are said to criss-cross between southern Gaza and Egypt's Sinai desert, providing a lifeline to Gaza residents who are starved of basic supplies due to Israel's blockade of the territory.

Sources say there are more than 6,000 Palestinians employed in the clandestine industry.