* Rights groups speak of relief gap in Sudan
* Say government has done nothing since expelling aid bodies
* Urge Khartoum to let aid groups back in
* Aid vacuum could overwhelm peacekeepers, groups say
By Frank Nyakairu
NAIROBI, April 8 (Reuters) - More than a month after Sudan shut down 13 foreign aid groups in Darfur, Khartoum has done nothing to fill the relief gaps, leaving 4.7 million people at risk, rights groups said on Wednesday.
Headed by international human rights watchdog Amnesty, 19 mostly African rights organisations urged Sudan to let back in aid agencies expelled after a Hague court indicted Sudan's president for war crimes.
"We are concerned that to date, more than a month after the decision to expel the organisations, the government of Sudan has not put in place measures to ensure that civilians will not die from thirst, hunger and disease," Mariam Kahiga, Amnesty International's Kenya coordinator, told a news conference.
Sudanese President Omar Hassan al-Bashir has threatened to throw out more relief groups following the International Criminal Court's decision last month to issue a warrant for him for crimes against humanity.
Khartoum says the shuttered organisations helped the court, a charge the aid agencies deny. A senior foreign ministry official said last month that Sudanese government agencies would cover the gap left by the expelled aid groups, with help from remaining foreign and local organisations.
The aid vacuum left by the expulsions now threatens to overwhelm the under-equipped international peacekeeping mission in Darfur, the rights groups said.
"If the decision to expel the aid agencies is not reversed, there is a risk that the African Union peacekeepers currently in Darfur with the joint United Nations African Union Mission for Darfur will be faced with the prospect of protecting a civilian population that is at the same time dying from hunger, thirst and disease," said Kanjethe Munagi of Kenya's Social Reform Centre.
"We consider it unacceptable that the government of Sudan responded to the arrest warrants by punishing the people of Darfur."
The rights groups urged the African Union and the U.N. Security Council to exert more pressure on Bashir's government to allow aid organisations to resume relief work.
International experts estimate some 200,000 people have died and 2.5 million have been driven from their homes during almost six years of ethnic and political fighting in Sudan's violent west. Khartoum puts the death toll at around 10,000. (Reporting by Frank Nyakairu; Editing by Giles Elgood)