A growing number of African migrants are being captured, held and tortured by Bedouin people smugglers in the Sinai region of Egypt.

The very smugglers they hire to sneak them across the border into Israel turn on them and hold them hostage to extort ransom money from their families, human rights groups have claimed.

Many of the migrants said they started out on their journeys to Israel from Sudan, where they established contact with Bedouin smugglers.

Not all of the smugglers were crooked and a number of them had safely gotten migrants across the border into Israel for a few hundred pounds.

Others seized the opportunity to make more money out of the migrants by holding them captive and contacting their relatives for money.

In some cases, smugglers resorted to torturing migrants while speaking to their families to increase the pressure on them to part with their cash.

While they have been in detention, migrants said they have been verbally abused and beaten, while they received little food or water.

Women have also reported being repeatedly raped by their captors.

Human rights advocates said the situation was worsening, as the smugglers turned to harsher methods of torture to extract more money - up to $40,000 (£25,000), AP reported.

Israel's interior ministry said 1,500 to 2,000 Africans, most of them from Sudan and Eritrea, enter the country each month.

Israeli Prime Minister Benjamin Netanyahu has recently pledged to inject more money into erecting fences along its border with Egypt.

There are also plans to build holding facilities for asylum seekers whom Israel cannot return to their countries of origin.