Photo taken on Oct. 16, 2016 shows South Sudan's government soldiers at the battle field in Alelo near South Sudan's northern town of Malakal. Fresh clashes between government and opposition forces near the northern town of Malakal have killed at least 56 over the weekend, a military spokesman said late Sunday. (Xinhua/Gale Julius)

JUBA, Feb. 6 (Xinhua) -- South Sudanese army (SPLA) said on Monday it carried out last week's air raid operations against rebels without alleged involvement of Egyptian forces.

Army spokesman Brigadier Lul Ruai Koang told Xinhua in an interview in Juba that the bombardment on rebel positions in Upper Nile, Jonglei and Unity states was solely carried out by the SPLA airforce.

"That was correct the aerial bombardment was carried out by the SPLA air force. The rebels were surprised because they were not aware the SPLA was developing its air force," he said.

However, rebel (SPLA-IO) spokesman Colonel William Gatjiath Deng insisted that the Egyptian air force was involved in the operations against them in Upper Nile state.

"It bombed Kaka West of Palouge at 1:00 pm, dropped 9 explosive shells on January 3. Wau Shulluk North West of Malakal dropped 6 explosive shells on January 1 and Owach dropped 6 explosive shells West of Malakal at around 8:00 pm. And this was an Egyptian Antenov. South Sudan has no Antenov since her independence," he told Xinhua.

"The Juba regime must be reminded that since the establishment of the South Sudan Air Force (SSAF) on June 24, 2008, South Sudan has only acquired one Beech 1900 transport aircraft, 2 Aero L-39 Albatross, 9 Mil Mi-17 Hip utility helicopters, 1 Mil Mi-172 Hip VIP passenger helicopter and 2 attack helicopter gunships," Gatjiath added.

Meanwhile, media reports quoted Egyptian foreign ministry spokesman Ahmed Abu Zeid denying the alleged air strikes, saying "Egypt does not interfere in the internal affairs of other countries."

The South Sudan conflict since its outbreak in December 2013 has tended to drag in several foreign forces with different strategic interests in the world's youngest nation.

The Ugandan army intervened at the height of the conflict in 2013, fighting against SPLA-IO rebels led by now exiled former first vice president Riek Machar before the UN and regional body Inter-Governmental Authority on Development (IGAD) piled pressure on Ugandan troops to pull out.

And also South Sudan's northern neighbor Sudan has for long been accusing Juba of harboring insurgents like the Justice, Equality Movement (JEM) and SPLM -- northern sector fighting to topple the Sudanese regime.

South Sudan has been shattered by civil war that broke out in 2013 after President Kiir accused his former deputy Machar of plotting a coup. Machar denied the accusation but then mobilized a rebel force.

A peace deal signed in August 2015 led to the formation of a transitional unity government in April, but was again devastated by fresh violence in July 2016.

Tens of thousands of South Sudanese have been killed, with over 2 million displaced and another 4.6 million left severely food insecure since the civil war.