Communities in the oil-rich region of Ogoniland say they feel just as marginalised and in need of work and development as they were before the executions of Ken Saro-Wiwa and eight other chiefs in November 1995.

The executions, which followed a kangaroo court that allowed no appeal, followed a peaceful uprising by 300,000 Ogonis against Shell’s widespread pollution in Ogoniland. They focused worldwide attention on the small 1,050 sq km region where the Nigerian oil industry first developed in the 1950s, but which was hit hardest by oil spills.

Despite worldwide awareness, the promise of a cleanup, and a UN report that urged government and oil company action, many communities still lack lighting and basic services, and fishing and farming is impossible in the many polluted areas.

“I don’t think anything has changed in terms of the Niger delta and the Ogoni environment,” said Parick Naagbanton, a conflict analyst with the British Council who founded the Center for Environment, Human Rights and Development in Port Harcourt.

“The benefits of oil revenue are still elusive. Delta communities still have no electricity, no basic services. And the oil spills keep happening.”

Shell was declared unwelcome and ejected by the Ogoni in the early 1990s, but its network of ageing pipelines that pass through Ogoniland still leak and are regularly vandalised.

“The main change in 20 years on the delta is that people are more conscious of the environmental horror they are forced to live in. Today they are demanding a cleanup. Before, they thought that it would not get worse and that government would be responsive. Now there is increasing disappointment. People are more organised and more concerned,” said Nnimmo Bassey, director of Health of Mother Earth group and former chair of Friends of the Earth International.

“There is a sense that development is passing them by. Violence is under the radar. It could flare up any time. Today there are many more NGOs and many more voices standing up for justice,” he said.

The 2011 UN Environmental programme (Unep) report, which recommended that oil companies spend $1bn cleaning up farmland and creeks, was important because it scientifically validated the long-standing complaints of local people. But four years on, not much has been done, said Ken Wiwa, the son of Ken Saro-Wiwa.

“I understand that people are up in arms that reparations have not been implemented. It requires cooperation and trust between communities, government and oil companies which we still do not have. Communities are still divided among themselves,” he said

“Things have changed for the worse in the last 20 years. People are more agitated now. They are very concerned about their environment. They do not trust oil companies or government. They have been left to their fate, [to] do anything they can to survive,” said Lazarus Tamana, European coordinator of the Movement for the Survival of Ogoni people (Mosop) which Saro-Wiwa and others set up in opposition to Shell and other oil companies working in the region.

“I have seen no government project here in years. There has been nothing to create jobs. People suffer diseases related to hydrocarbons and pollution. The situation is terrible. The youth have no sense of direction. The region is very volatile. It is quite dangerous again. Communities that have not benefited are organising themselves for serious protest against Shell. Anything can get out of hand,” he said.

Owens Wiwa, Ken Saro-Wiwa’s brother, was slightly more optimistic. While he said cleanup of the oil spills had largely not happened, the Delta has seen a small reduction in gas flaring.

“If you go to Ogoni now, compared to what it was in 1995, you will see quite a lot of grains. The farmers talk of better yields. They don’t have as much pollution from gas flaring,” he said.

There are social changes happening too. “The people are much more aware of their environment and of their rights,” Wiwa said. “More people are involved in civil society both in Ogoni and also in Port Harcourt. That’s a huge change. We have a critical mass of young people who are getting involved,” he said.

But those bright spots are set against other, darker challenges. Wiwa said poverty and hopelessness has increased, largely due to a lack of basic infrastructure.

“The government has not invested in Ogoni at all. One can almost wonder whether it is a punishment to the Ogoni people because they are not allowing oil drilling by Shell,” Wiwa said.

Shell responded by saying that it has trained more than 6,000 young people from the Niger Delta in enterprise development and management since 2003, contributed $14.8m in scholarships and other education programmes in 2014, and continues to subsidise healthcare.