A group of 54 Israelis petitioned the High Court of Justice on Thursday seeking a criminal investigation into Israelis exporting arms to South Sudan on possible charges of war crimes and crimes against humanity.

The petitioners, some of whom work with human rights groups, were brought together by attorney Eitay Mack about a year and a half ago. Mack has filed a number of legal actions and has liaised with government officials demanding greater transparency and oversight of Israel’s arms trade.

He has sought to uncover what he has called “Israel’s connection with regimes committing crimes against humanity, war crimes and [other] serious violations.”

Thursday’s petition cites reports on the transfer of Israeli-made Galil ACE rifles to militias of the South Sudanese government, which is said to have used them against members of the Nuer tribe, setting off the country’s civil war at the end of 2013.

“Officials at the foreign and defense ministries in Israel should have known the risk they were taking in approving a dubious rifle-export transaction,” the petitioners say. “Could there be one employee at the foreign and defense ministries for whom it sounds reasonable for a country's president to place a ‘private order’ for rifles for his private militia?”

South Sudan gained its independence from Sudan in 2011. The civil war broke out after President Salva Kiir of the Dinka tribe accused his former deputy, Riek Machar of the Nuer tribe, of planning a coup. Both sides have been accused of committing war crimes including massacres, gang rapes and the burning of women and children in their homes.

In August 2015, the sides reached a peace deal under the threat of additional sanctions by the UN Security Council, including an arms embargo. The Security Council later imposed sanctions on both sides and a committee of experts was set up to monitor implementation.

Last year Haaretz reported that Israel had supplied wiretapping equipment to South Sudan, letting the regime monitor its opponents. An interim UN report stated that the South Sudanese army was using Israeli-made weapons it even included pictures of soldiers armed with ACE assault rifles, an updated version of Israel Military Industries’ Galil rifle.

When members of the committee came to Israel to meet with officials from the foreign and defense ministries, they were told that the weapons in question had been sold before the civil war, and that Israel had halted the sale of offensive weapons to South Sudan in early 2014. Israel pledged that this policy would remain in force.

A final UN report largely accepted the Israelis’ contentions, even though it found that both the ACE and another Israeli rifle, the Micro Galil, were widespread in South Sudanese war zones. The report also stated that the government forces’ ACE rifles were bought before the civil war began. Israel continued to allow the export of military equipment that was deemed defensive.

The petitioners seek a court order requiring Attorney General Avichai Mendelblit and State Prosecutor Shai Nitzan to explain why a criminal investigation was not opened against the holders of the arms export licenses. They also want to know why the foreign and defense ministry officials who approved the sales were not investigated as possible accessories to war crimes and crimes against humanity.

Since January 2016, Mack has repeatedly been told by Mendelblit and Nitzan’s offices that his request was passed on to the relevant people. “It is inconceivable that [Mendelblit and Nitzan] would ignore concrete evidence of abetting crimes against humanity and war crimes,” the petitioners say.

In another high court filing in 2016, Mack sought to get revoked the export licenses for the wiretapping equipment.