KHARTOUM, April 13 (Xinhua) -- Two voters were killed and a candidate was wounded in the Unity State in South Sudan on Tuesday, the third polling day in Sudan's general elections, an opposition leader said.

"Two voters were killed and a candidate was wounded when the Sudan People's Liberation Army (SPLA) soldiers opened fire on the voters at a polling station in the Unity State," Lam Akol, the chairman of the Sudan People's Liberation Movement-Democratic Change (SPLM-DC), told Xinhua here on Tuesday.

The SPLA is the military arm of the Sudan People's Liberation Movement (SPLM), the dominant party in South Sudan.

Akol, the only candidate contesting against SPLM Chairman Salva Kiir Mayardit for the post of South Sudan government president, went on saying that "the SPLA opened fire randomly, which resulted in the deaths of two voters and injury of one candidate."

Akol slammed at the SPLM, saying "the ministers and commissioners belonging to the SPLM and SPLA are intervening in the polling operations and threatening the citizens."

He added that commissioners of western and eastern Bahral- Ghazal states took the ballot boxes to their homes.

He called on Sudan's National Elections Commission (NEC) to take necessary measures to protect the voters and prevent the harassment made by the SPLM supporters.

No comment so far has been made by the South Sudan government or the SPLM on the incident.

The former rebel SPLM in South Sudan signed the Comprehensive Peace Agreement (CPA) with Khartoum in 2005 to end a two-decade civil war between the north and the south, and has become a partner of the ruling National Congress Party in the current Sudanese government.