By Emam El-Leithy – El-Arish, Egypt
"Tunnels mean life for our people," said a Palestinian elder who lives in the Egyptian city of El-Arish, giving his names as Ismail.
"As Israel tightens the grip on our people, tunnels become the only way to help them with the basics needed to survive."
An unspecified number of tunnels stretches along the 14-kilometre (eight-mile) border between Gaza and Egypt.
The subterranean passages have become the lifeline for the 1.6 million people of the impoverished strip since Israel sealed it off in June 2007.
"In the beginning, tunnels were used to smuggle packed food and cigarettes," recalls Ismail.
"But now, tunnels are being used to transfer flour, sugar and other badly-needed foodstuff."
He added that the Israeli siege on the densely-populated enclave prompted Palestinian to build bigger tunnels.
"There are tunnels for pumping highly prized diesel and petrol for fuel-starved Gaza. There are also tunnels as high as 1.5 meter to move livestock from Egypt into the besieged strip."
Ever since Hamas won the legislative elections three years ago, Israel has imposed ever tighter economic pressure on the Gaza Strip.
For a year and a half now, the siege amounted to a punitive blockade under which all exports were banned and only a restricted list of humanitarian goods were allowed in.
Tunnels are supplying fuel, domestic goods and livestock, in what a UN report last year described as a "vital economic lifeline" to a Gaza under blockade.
Ismail, the Palestinian elder, gave a glimpse on the construction of tunnels.
"The tunnel’s depth ranges between 18 to 30 meters," he told IOL.
"The tunnel’s opening is often stepped with concrete pillars to avoid any collapse."
Ismail says the main bulk of tunnel construction happens on the Palestinian side of the border.
"The longest part of the tunnel is often within Gaza."
He noted that the process could be very expensive.
"Tunnels could cost $60,000 each while smaller ones cost only $5,000."
Ismail says the first tunnel was built following the 2000 Palestinian intifada.
"It was built between two houses in the Egyptian and Palestinian sides of Rafah."
He said the owner of the Egyptian house was given 100,000 Egyptian pounds ($18,000) to build the tunnel’s opening inside his bedroom.
He said people transporting goods in and out Gaza use bells to alert each others inside the tunnels in case something comes up.
Ismail added that the tunnels are often lit with gas lamps.
"Every 15 meters people put a lamp in order to help them move into the tunnel."
Like many involved in the tunnel business, Ismail denies Israeli claims that weapons are being smuggled through tunnels into Gaza.
"We don’t smuggle weapons," he said emphatically.
"Most merchants and tunnel owners are not dealing in weapon smuggling."
He said that bringing weapons into Sinai is almost a "mission impossible".
"Smuggling weapons through Sinai is very difficult and dangerous."
He insisted that Palestinians had never had a problem getting weapons, even when Israel was occupying Gaza.
"The weapons are largely smuggled through Israel. Hamas and other factions even buy the weapons from Israeli soldiers."
Arms smuggling through tunnels was one of the main Israeli pretexts for its 22-day onslaught which left Gaza, home to 1.6 million people, in ruins.
The Israeli government has warned that it would batter Gaza again to destroy the tunnels.
"Israel reserves the right to react militarily against the tunnels once and for all," Foreign Minister Tzipi Livni told public radio on Thursday.
Ismail said the Israeli offensive has only destroyed nearly 40 percent of Gaza tunnels.
"But the rest of the tunnels are intact and are ready for business."
Ismail said the tunnels have also become a source of living.
"The person who moves goods from one side of the tunnel to the other is paid nearly $20 an hour," he said.
"The spool worker is given between $10 to $15 per hour while the one who is in charge of the tunnel’s opening on the Egyptian side is given $30 on every smuggling operation."
The tunnel business has also become important for the economy of northern Sinai.
"I earn nearly $100 per day from tunnel trading," Ahmed, an Egyptian merchant, told IOL.
He said many Egyptians in Sinai don’t find jobs and government salaries are not enough to make ends meet.
"I can’t imagine my life without the money we earn from our trade dealings with Gaza.
"Our trade and life is totally dependent on the strip."
Egyptian authorities often slap harsh sentences on people found involved in tunnel smuggling.
"My relative got three years in prison after a tunnel was found inside his house," one merchant told IOL, requesting anonymity.
He blamed Israel for the bustling tunnel trade, saying the Palestinians and Egyptians used to move freely across the borders before 1982.
"We used to have trade with the Palestinians even before the Israeli occupation of Sinai in 1967. Now they want to prevent us from this," he said.
"Now I can’t move into Gaza to see my mother," added the merchant, born to an Egyptian father and a Palestinian mother.
"But tunnels help me to get into Gaza to see my mother."
Many Egyptian merchants say the closure of Rafah crossing, Gaza’s only window to the outside world, is promoting the tunnel trade.
"We smuggle goods through tunnels to earn a living," said Mahmoud, an Egyptian merchant.
"To avoid smuggling, they must open up the border crossings."
Hussein, who transfers goods through tunnels into Gaza, agrees.
"We don’t want to violate any laws, but there are a lot of goods here that don’t find a buyer, while there are thousands in Gaza who don’t find anything to buy."
He believes no one would be able to stem smuggling into Gaza.
"This can only happen if they permanently open the Rafah crossing."