A prominent opposition leader in Sudan said the ruling military forcibly deported him and two of his colleagues to South Sudan.

"I was deported from Sudan against my will... I was deported to Juba in a military aircraft," Yasir Arman, deputy head of the Sudan People's Liberation Movement-North (SPLM-N) faction led by Malik Agar, told reporters at a hotel in Juba on Monday.

The opposition leader was released and deported to Juba along with the opposition movement’s secretary general Ismail Khamis Jalab and its spokesperson Mubarak Ardol.

Arman further said he had been well received by South Sudan government.

Arman had arrived in Khartoum in late May to participate in peace talks with the ruling military council after the ouster of president Omar al-Bashir in April.

The deportation comes on the second day of a nationwide civil disobedience campaign in Sudan, in protest against the deadly crackdown on protesters.

Arman's SPLM-North movement has been fighting against Sudanese armed forces in Blue Nile and South Kordofan states since 2011.