The two Ugandan journalists arrested over the weekend by South Sudan's national security officials are still in detention, an official has said.

Justin Dralaze, a Uganda based Reuters' reporter and Hilary Ayesiga, a photographer with the same media outlet covering East African region including South Sudan were arrested on Saturday after arriving in Juba on Friday.

According to the Ugandan Embassy in Juba, the two journalists were due to be released on Tuesday but their release was pushed to Wednesday since Tuesday was Martyrs Day in South Sudan.

Oliver Modi, the Chairperson of the Union of Journalists of South Sudan (UJOSS) said he personally met the two including a local journalist working for Liberty FM (Sunday David Tut) last evening after talks with the security officials.

"I went there personally and met the security and talked to them. What I found was that the journalists were advised to wait for accreditation on Monday because on Saturday the office does not work but they started work before," Modi said.

The two journalists are however said to be in good health. "I was allowed to meet them-(journalists) and I talked to them. They look fine, they are not tortured. They are undergoing investigation," Modi added.

On Saturday the two decided to go to the streets of Juba and started filming which prompted their arrest by the security agencies.

According to Modi, the security officials have accepted to release the journalists in the next 24 hours after the investigation.

Modi appealed to foreign journalists to undergo the necessary legal procedures when in the fledgling nation and urged national journalists to also register with the union (UJOSS).