Iran's smuggling network to Gaza has shrunk following Operation Cast Lead, and international awareness of the issue has increased, according to Western and Israeli intelligence sources.

According to Western intelligence reports, Iran has been maintaining a robust arms smuggling system into the Gaza Strip as part of the support it extends to Hamas. This support is set up in a modus operandi similar to the one Iran has employed for two decades in helping Hezbollah in Lebanon through Syria.

The route through which arms are moved from Iran to Gaza seems to have become more complicated. Currently, it appears weapons shipments are dispatched through Bandar-Abbas, a southern Iranian port. From there the shipments are transported to Yemen, through the Persian Gulf.

The weapons go from Yemen to a Sudanese port, from where they are transported by professional smugglers to Egypt and onto the Sinai peninsula. From Yemen to Sudan, the arms are transported inside the hulls of medium-sized civilian boats.

According to the London-based Sunday Times and other media, the Israel Air Force used unmanned drones to attack secret Iranian convoys in Sudan last March; the convoys were said to be smuggling weapons to Palestinian militant organizations in the Gaza Strip.

But usually shipments from Sudan make it over to Bedouin smugglers, who transfer the shipments into the Sinai and get the goods over to the Egyptian part of Rafah. From there it is smuggled in tunnels to the Palestinian part of town, which is the terminus.

The weapons are mostly Chinese-made, but some are manufactured in Iran. This includes medium- and short-range rockets, anti-tank missiles, explosives and firearms.

A recent study by the Palestinian Center for Democracy and Conflict Resolution showed that more than half the 16,000 people working in the tunnels are under 18, as were 30 of the 115 people killed in the tunnels since Israel imposed the blockade two years ago.

The Hamas government says the tunnels are legal until the blockade is lifted, and the Rafah municipality charges a NIS 10,000 shekel ($2,500 dollar/1,800 euro) fee to open one.

On the way back from Sudan to Yemen, the smuggling boats are often used to smuggle African foreign workers into Asia or for contraband products. United States Navy vessels found several of these boats. One, searched during routine security patrolling in the Red Sea, contained a large shipment of jams.

Israeli intelligence sources report that after Operation Cast Lead, the Egyptian security forces are more willing to cooperate with their Israeli counterparts. Coordination is done through phone calls between relatively high-level officials.

Israel has reportedly carried at least out three air strikes since January against what was believed to be Iranian arms shipments passing through Sudan on their way to Gaza, according to the American news network ABC.

Sudanese officials confirmed that in January, in the wake of Israel's assault on Hamas-ruled Gaza, unidentified aircraft attacked a convoy of 17 trucks heading north through eastern Sudan.