A variety of goods are smuggled through the tunnels to Gaza
By Christian Fraser
BBC News, Rafah, Egypt
Abu Mohamed is an olive farmer. His land runs parallel to Gaza's perimeter wall. For three months he has been running a tunnel from one of his fields.
It's a lucrative business. He earns up to 20,000 Egyptian pounds ($3,500) every 10 days.
His tunnel is about 500 metres (550 yards) long and almost 30m deep. Below the trap door there is a storeroom where the Palestinians wait for the goods.
He has a motorised pulley to lower heavier items. He takes orders for cigarettes, sugar, tea, medicine, livestock, even fridges, which are dragged to the other side on ropes.
But from time-to-time his tunnel is used to move weapons.
They are delivered to his door by a middleman.
"I think it is TNT," he said, "or some of the materials they might use to make rockets.
"It always comes in a sealed bag. I never open it to look. It's not my business."
The middleman who brings the bag also controls the money. The Palestinians pay into a Egyptian bank account.
The money is held in trust and then divided among the farmers.
I asked Abu Mohamed how they manage to dig these tunnels with such precision.
"We stand in the field with a white flag," he said.
"They measure the distance from the other side - and then I direct them, as they dig, from the markers they push through the soil.
"The tunnel comes up on my side, if I let them dig it further to the house next door, I get even more money."
Israel has destroyed some tunnels, such as this in Gaza
But now his tunnel is closed. It was bombed by the Israelis last week.
The Israelis estimate there are 300 tunnels that extend from Egypt into Gaza.
The people in Rafah tell me there are twice that many, though a lot have been demolished in the past week.
The Israelis have pounded the land between the perimeter wall and the houses on the Palestinian side.
They are targeting scores of plastic tents that hide the entrances to the tunnels and now the houses as well.
On Tuesday night they dropped tens of thousands of leaflets warning Palestinians to move out.
Hundreds of families have been made homeless.
One Bedouin smuggler told me that some smuggling continues but in the past week most of the goods that they have sent have been thrown over the wall.
At night from our camera position we have heard the smugglers from the Palestinian side shouting instructions to their waiting Egyptian counterparts.
There are tunnels of many different sizes along the wall, for many different uses. I have seen a tunnel with an entrance beneath a wardrobe, and others that were hidden in the undergrowth beside the wall.
Some are used to move fuel, some to run electric cables, others to move people.
After 18 months under an Israeli-imposed siege, the Palestinians say the tunnels are their lifeline.
The tunnels have been destroyed before. It only disrupts business, it doesn't stop it.
On the Egyptian side the local economy has been badly hurt by the bombing raids.
Tawfiq Nafal, the manager of a hardware store, says he is now stuck with orders he cannot move.
"Every few days I would receive an order from the other side," he said.
"Recently I got one for 500 paint buckets. A man came to collect them. He didn't tell me where they were going but I knew.
"Rafah is one town. For Palestinians there is always a cousin on the Egyptian side who can make the order.
"If Egypt was really interested in enforcing the blockade they would have closed these tunnels in 15 minutes. We are the people who have helped the Palestinians the most."
Tariq, another trader, who also confessed to being a tunnel operator, says since the blockade was enforced the Egyptian side of Rafah has seen a threefold increase in the local economy.
"What I buy for one Egyptian pound I can sell to them for five Egyptian pounds," he said.
Some traders say since the bombing began there have been arguments between Egyptians and Palestinians, on who should pay compensation for goods that were lost in the tunnels.
But all of them agree that unless the blockade is lifted the trade will start again.
"The tunnels have been destroyed before," said Tariq.
"It only disrupts business, it doesn't stop it."