Nigeria’s state oil company and its joint venture partners have spent $360 million on cleaning up the Niger Delta oil heartland in the past two years, the Nigerian National Petroleum Corporation (NNPC) said on Monday, but locals said little work had been done.

Nigeria is Africa’s biggest crude oil exporter. Oil sales account for around 90% of its foreign currency earnings but oil spills in the southern Niger Delta region have caused pollution and angered locals.

Royal Dutch Shell Plc was forced out of Ogoniland in 1993 by campaigners led by activist Ken Saro-Wiwa, after they said the oil company had destroyed their fishing environment. Saro-Wiwa was later hanged by the military government, prompting international outrage.

A 2011 United Nations report warned of catastrophic pollution in soil and water in Ogoniland. It said Shell and Nigeria’s government needed to address the problems.

In 2015 Shell accepted responsibility for operational faults that caused two spills in 2008.

Shell paid a settlement of 55 million pounds to villagers and since then has said it has taken steps to improve the situation in the area, including training youths to start up businesses and funding community patrols to reduce pollution by vandals stealing oil.

NNPC and its joint venture partners of Shell Petroleum Development Company (SPDC), Total Exploration and Production of Nigeria (TEPNG) and Nigerian Agip Oil Company (NAOC) “have disbursed $360 million toward the Ogoniland clean-up project,” NNPC Chief Operating Officer for Upstream, Roland Ewubare told lawmakers during a presentation on Monday.

Ewubare said the $360 million was out of a total $900 million recommended by the United Nations Environment Programme (UNEP). He said NNPC and it partners were ready to fund the project as prescribed by the UNEP report.

But a number of locals questioned the impact of the operation.

“What they are touting as a cleanup is substandard,” Christian Kpandei, a fish farmer whose land was polluted, said in an interview with Reuters.

Morris Alagoa, of the Environmental Rights Action (ERA) campaign group, said he had seen little activity since the operation began.

But a photograph seen by Reuters taken in the last few weeks in Bodo, which sits in Ogoniland, showed men wearing overalls and hard hats beside boats, suggesting some activity.

A spokesman for NNPC said the company and its partners merely distribute funds, which they have done.

REUTERS