Four Nigerian women at the centre of a long-running legal battle against oil giant Royal Dutch Shell saw their historic case reach the Hague on Tuesday.

The company is accused of complicity in the state execution of nine Ogoni protesters and human right abuses dating back to 1993. The allegations concern the 1990s violent government crackdown in Ogoniland, in the oil-rich Niger delta region, where oil spills inflicted environmental damage on a huge scale.

The Netherlands court will decide whether a case can proceed after hearing arguments from both sides on Tuesday.

Facebook Twitter Pinterest Victoria Bera (left) and Esther Kiobel outside the court room in The Hague. Photograph: Pierre Crom/Getty Images

The landmark case, brought by the widows of four of the Ogoni nine – Esther Kiobel, Victoria Bera, Blessing Eawo and Charity Levula – allege Shell was complicit in the Nigerian government’s policy of brutally quelling protests, and with human rights abuses that were aimed at protecting the company’s staff and infrastructure, actions that ultimately led to the death of their husbands.

Peaceful demonstrations by Ogoni people against Shell’s widespread, devastating pollution ended in a brutal backlash by Nigerian security forces, who allegedly killed, maimed, raped and tortured hundreds of people who lived in the area.

Nine members of the Movement for the Survival of the Ogoni People (Mosop), including its leader, Ken Saro-Wiwa, were executed in 1995 by the Nigerian authorities, following a trial that was widely discredited. Esther Kiobel’s husband, Dr Barinem Kiobel, was one of those executed.

“Over the years, Shell has continually fought to make sure this case is not heard in court. They have the resources to fight me instead of doing justice for my husband,” said Esther Kiobel.

Facebook Twitter Pinterest Ogoni Day demonstration in Nigeria, 1993. Photograph: Tim Lambon/Greenpeace

The 1993 military coup in Nigeria, led by General Sani Abacha, brought a clampdown on political activity, with opponents jailed or executed. A new security task force (ISTF) focused on Ogoniland, applying brute force in an effort to end the protest. During its first deployment they shot five people outside Shell’s compound at Rumuobiokani.

Amnesty International has reported that ISTF carried out up to 50 extrajudicial executions, alongside torture and rape. The government’s forces left hundreds more dead and many more homeless when villages were destroyed.

Facebook Twitter Pinterest Ken Saro-Wiwa addressing Ogoni Day demonstration in Nigeria, 5 January 1993. Photograph: Tim Lambon/Greenpeace

In May 1994, four Ogoni leaders – Edward N Kobani, Albert T Badey, Samuel N Orage and Theophilus B Orage – were attacked and beaten by an angry mob, who then set their corpses on fire.

Blaming the deaths on internal Mosop wrangling, ISTF arrested Saro-Wiwa, Kiobel and 12 others and charged them with incitement to murder, and murder. Nine were found guilty – Barinem Kiobel, Ken Saro-Wiwa, Baribor Bera, Saturday Dobee, Nordu Eawo, Daniel Gbokoo, John Kpuinen, Paul Levula and Felix Nuate – and were hanged in November 1995.

Unable to seek recourse in Nigerian courts, Esther Kiobel first filed a case against Shell in the US in 2002. The company deny allegations of complicity in the death of the Ogoni nine or in the widespread human rights abuses, although it acknowledged an awareness of Nigeria’s military action to protect its infrastructure. In 2009, Shell agreed a $15.5m out-of-court settlement with the families of the dead men, stating that it was to cover their legal costs and recognition of events that took place in Ogoniland. The US court declined jurisdiction and in 2017, with the assistance of Amnesty International, the case was re-filed in the Netherlands.

In a letter to Amnesty International in June 2017, Osagie Okunbor, managing director of Shell-Nigeria, refuted allegations of misconduct and said, “We were shocked and saddened when we heard the news of the executions. Shell Nigeria appealed to the Nigerian government to grant clemency.”

Mark Dummett, researcher at Amnesty International, said: “These women believe that their husbands would still be alive today were it not for the brazen self-interest of Shell. This is an historic moment which has huge significance for people everywhere who have been harmed by the greed and recklessness of global corporations.”

This morning at the Hague, plaintiffs Esther Kiobel and Victoria Bera gave evidence to the court. Blessing Eawo and Charity Levula were unable to attend. Presenting the response from Shell, barrister Wemmeke Wisman stated that the company denied the allegations made by the two women, and argued that the matter should not proceed on the basis of statutes of limitation in Nigeria.

In addition they asked the court to consider whether it should decline jurisdiction on the basis that Shell-Nigeria operated independently of its parent company, Royal Dutch Shell. The case was adjourned to 8 May, for the judge to decide whether the proceedings should be stayed or whether examination of further evidence was needed.

Speaking to the Guardian at the conclusion of Tuesday’s hearing, Esther Kiobel said: “I am happy that I have had my day in court to tell the judge that I want justice and all the hanged men exonerated.”

Facebook Twitter Pinterest Oil from a leaking pipeline burns in Goi-Bodo, a swamp area of the Niger delta, in 2004. Photograph: Reuters

In 2011 a UN Environment Programme report revealed extensive contamination of Ogoniland’s agricultural land, fisheries, drinking water, with hundreds of thousands of people suffering from environmental-related illness. In 2018 the Nigerian government announced a $1bn rescue programme aimed at tackling damage.