The United Nations is closely watching developments in South Sudan. The UN refugee agency says heavy fighting and a lack of food in two South Sudanese states are forcing more people to flee their homes. It says more than 100,000 people have been displaced over the past two months.
The government in neighboring Sudan has denied it is involved in the South Sudan conflict. But a new report suggests Sudan's government may be supplying arms to the rebel opposition in the South by airdrop. The report says the supposed flow of weapons has helped fuel the fighting.
South Sudan became independent from Sudan in 2011, but a civil war started less than two years later. South Sudan's military and opposition forces first clashed in December 2013.
The new report comes from a private group called Conflict Armament Research, which is based in Britain. Its members investigate arms trafficking and use of weapons in armed conflicts.
The report describes in detail the weapons that the military, also known as the SPLA, seized from the opposition last year. It says the SPLA captured about 300 rounds of small-caliber ammunition and some larger artillery in Jonglei state from the rebels. Markings on much of the ammunition suggest it was made in Sudan in the past few years.
Jonah Leff is the director of operations for Conflict Armament Research. He says the manufacturing dates suggest Sudan is directly involved in supplying the rebels.
"Most likely any ammunition manufactured in 2014 most likely hasn't changed hands many times, which suggests, like in previous years, that Sudan may have supplied this ammunition directly to the SPLA in opposition."
His group says some of the ammunition rounds were manufactured in China. It says they appear similar to those used in a rebel attack on an Islamic religious center in April 2014. The United Nations says 287 civilians were killed in the attack.
The report says the supplies must have been dropped from the air. Jonah Leff says this finding was based on the damage found on some of the ammunition.
"The impact, once the equipment hits the ground, even if it's packaged in crates, sustains some damage. So we noticed, for instance, with the small caliber ammunition, some of the rounds were bent and misfigured. The larger ammunition were stored in tubes that had also bent and jammed up so that you weren't even able to open them."
Mr. Leff says the researchers are almost sure the ammunition was dropped by air. But he adds that they cannot confirm that it came from Sudanese aircraft.
Sudan's government has repeatedly denied reports it is arming the South Sudanese rebels. The government says it has no interest in deepening the conflict in South Sudan.
The new report, however, notes that some of the ammunition documented is similar to equipment Sudan has supplied to rebel groups in the past.
Fighting in South Sudan has intensified in recent weeks as the SPLA and rebels battle for control of oil fields in Upper Nile state.
The African Union recently expressed support for a United Nations call for a ban on arms exports to South Sudan as a way to stop the conflict. The AU also supported actions to punish those responsible for the violence.
I'm Kelly Jean Kelly.