Ahmed Abdo was still asleep in his hut at the gate of the Aqua-Sun beach resort on Egypt's Red Sea coast when 20 masked men carrying guns burst in.

Abdo, 30, and his two colleagues were tied up, their mobile phones taken. The intruders, members of the Bedouin Tarabeen tribe, demanded money – 4m Egyptian pounds (£420,000) – from the owner in compensation for the land on which the resort was built. It belonged, they said, to the Tarabeen.

When the owner demurred, "they took everything – air conditioners, generators, televisions, gas canisters, even the doors," said Abdo. He showed the Guardian around the deserted and ransacked resort: doors kicked in or missing, mattresses taken from bed frames, windows smashed, cushions and rugs seized. The office had been stripped of equipment and furniture; room occupancy charts and leaflets were strewn across the floor. Ten fridges and a huge freezer had gone. Air conditioning units were torn from walls. They even tried to take the pool table, but dropped it mid-heist, leaving it lopsided on buckled legs. The value of goods taken is estimated at more than £100,000.

"Of course I was frightened," said Abdo. "We told them we are only workers here, we need to feed our children." Fortunately, there were no guests at the Aqua Sun at the time of the raid three weeks ago, a combined result of the low season and the impact of Egypt's upheavals on tourism.

The police, said Abdo, had not intervened. A highway patrol passed the resort as it was being looted but "they minded their own business". A local police chief has since advised the Aqua Sun's owner "to solve the problem with the Bedouin because it's not a good time for us to go into confrontation with them," according to Abdo.

The raid on the Aqua-Sun, apparently carried out by a small group of Tarabeen men living outside the immediate area, is one of a string of incidents in the Sinai over recent months. In south of the peninsula, it includes tourist kidnappings and armed robbery; in the north, it is more serious – the repeated bombing of a gas pipeline, the smuggling of people, arms and drugs, and a rise in militant Islamism.

What connects them is a new assertiveness among the region's Bedouin after decades of marginalisation, neglect and discrimination, as well as a growing security vacuum following the fall of former president Hosni Mubarak.

Israel, whose border with the Sinai runs for some 240km (150 miles), has viewed the spate of attacks over the past year with alarm. "Measures are needed to prevent the total collapse of security in and around the peninsula [and] avoid the rise of an armed runaway Bedouin statelet," wrote the Israeli analyst Ehud Yaari in a report, Sinai: A New Front, for the Washington Institute for Near East Policy last month. He described the peninsula as a "new hotspot … with an expanding terrorist infrastructure" and a wild frontier.

In the past 13 months, a pipeline which carries gas through north Sinai to Israel and Jordan has been attacked by militants 12 times, most recently just over a week ago, disrupting flow and causing millions of dollars of damage.

Armed gangs are trafficking huge numbers of people fleeing persecution, war or poverty from rest of Africa, charging thousands of dollars for passage across the Sinai into Israel. Camps have been established, from which emanate horrific stories of rape, torture, extortion, misery and desperation.

Smuggling across the border has become an industry: arms and goods to Gaza; marijuana and refugees to Israel. According to Yaari, the annual worth of this parallel economy was estimated to have exceed $300m (£190m) last year.

Israeli intelligence officials claim Hamas and other Islamic groups are working with militants among the Bedouin to launch operations against Israel. They are "turning Sinai into another arena from which terrorist activity can be launched", said Major General Aviv Kochavi, head of Israeli military intelligence, earlier this month.

A cross-border attack last August in which eight Israelis were killed was carried out by Bedouin militants from the Sinai, Israel's military concluded last month, having initially blamed a Palestinian militant group in Gaza, several of whose members had been killed in retaliatory attacks.

In response, Israel is rapidly constructing a fence – 5 metres (16ft) above ground, 1.5 metres below, reinforced with razor wire – along its border with the Sinai peninsula. It has also relaxed its insistence on Egypt demilitarising the peninsula under the terms of the 1979 peace treaty between the two and has boosted its own military presence along the border.

Hostage-takings in the past month have included the kidnapping of 19 Egyptian border guards after the death in custody of a Bedouin man; 25 Chinese cement workers, held for four days; as well as separate incidents in the south involving two US and three Korean tourists who were visiting St Catherine's monastery. All were subsequently released unharmed. But in Sharm el-Sheikh, a French tourist was shot dead and four others injured last month in an armed robbery at a bureau de change.

Many observers say lawlessness and anarchy has soared, particularly in northern Sinai, since Mubarak fell a year ago. But the region has long been semi-detached from the rest of Egypt and largely beyond the iron grip of its security forces.

It has suffered from chronic under-investment in education, health and transport. Its inhabitants are among the poorest in Egypt. Added to the potent mix of poverty, alienation and tribal loyalties is a sizeable Palestinian population in the north of the peninsula, with family, political and economic connections to Gaza.

In the south, massive investment since the 1990s in upscale resorts in the former Bedouin fishing village of Sharm el-Sheikh, and a programme to create a "Red Sea Riveria" along the coast, has further alienated the Bedouin.

The resorts, aimed at wealthy Cairenes and foreign tourists from Europe, the Gulf States and – until a series of bomb attacks in 2004-06 – Israel, rarely offer jobs to Bedouin, preferring to import Egyptian labour from Cairo and other Egyptian cities.

"This is the land of the Bedouin, but the hotel owners don't want any Bedouin in their hotels. Even the women are not allowed to sell beads on the beach," said 20-year-old Fedayah Rebabah in Nuweiba.

Many of the international chain hotels offer all-inclusive packages, ensuring that tourist cash does not find its way into local pockets. Locals have been largely restricted to offering "Bedouin experiences" of camel rides and tea-brewing to tourists.

The Egyptian tourism authority has allocated land along the coast for resort development, pushing the Bedouin into smaller enclaves or further inland to the desert. And many of the tribes are now demanding compensation for land which they say historically belongs to them.

"Aqua-Sun is on Tarabeen land," said Sheikh Amsalaam Faraj, 42, while adding that he and other senior tribesmen were angry at the seizure of property at the resort, which he blamed on "crazy people" within the tribe. "This is not the right way to do things. This has made a problem for the whole area." Tarabeen leaders were working a deal to resolve the crisis, he said.

Ayman Moeed, manager of Aqua-Sun, said its owners were effectively being asked to pay for the land twice. He said security was a big problem: the Egyptian army "is not here very much" and the police have little authority over the Bedouin.

But the main change, he said by phone from Cairo, was the revolution. "In the Mubarak era, there was a strong government and the Bedouin were kept in a box. They didn't say anything or do anything. But now they have freedom to do what they want. The Bedouin are the power now, and they're trying to take the land."

Suleiman Rebabah, 24, and his cousin Salama el-Fahd, 38, agree the Bedouin have felt more powerful and assertive since Mubarak's departure. "Now you can go everywhere," said El Fahd. "For work, it is worse [since the revolution] but for freedom, it is better," said Rebabah.

Back at the Aqua-Sun, another deadline for a deal passed last Friday without a resolution. According to Moeed, it was down to "the big men of the Tarabeen" to broker a compromise over the property. For now, the plundered resort remains deserted behind padlocked gates.

• This article was amended on 20 February 2012, to make clear the date of the attack shown in the photograph.