(CNN) -- The fate of dozens of construction workers kidnapped in Sudan, including a group of Chinese nationals, remained unclear Tuesday amid conflicting reports on the situation.
Militants captured 70 workers -- a mix of local and foreign staff -- in an attack Saturday on a construction site in a remote area of Sudan's volatile South Kordofan state, the Sudanese military said. The military said it was pursuing the kidnappers.
The camp belonged to China's Power Construction Corp. -- an example of the willingness of Chinese companies to push into unstable regions of the world in search of resources to help fuel the country's fast growing economy.
The official Sudan News Agency reported Monday that the Sudanese army had freed at least 14 of the kidnapped Chinese nationals, citing Ahmed Haroun, the state governor.
But that conflicted with information from Xinhua, the state-run Chinese news agency, which said later Monday that the 29 Chinese workers abducted by the rebels were still being held captive.
Citing an unidentified official at the Chinese Embassy in Sudan, Xinhua said that 17 other Chinese workers from the camp who fled the attack had been moved to a "safe location" by the Sudanese Army.
Footage from CNN affiliate CCTV showed the 17 Chinese nationals arriving Monday in Khartoum, the Sudanese capital, along with workers from another camp. Another Chinese national is still unaccounted for.
The Chinese Embassy has sent a four-person work group to assist the Sudanese authorities in the rescue of the hostages, the embassy official told Xinhua.
The Sudanese military said it believed the Sudan People's Liberation Movement-North, a rebel force in the border region with neighboring South Sudan, was responsible for the attack and kidnapping.
South Sudan became the world's newest nation last year after decades of conflict with the north.
International concern has grown over the violence in South Kordofan and nearby Blue Nile states, which has forced hundreds of thousands to flee their homes. The region is a Sudan territory but straddles Sudan and South Sudan's ethnic and political lines.
In a statement Tuesday, the Chinese Ministry of Foreign Affairs called for the quick release of the Chinese workers and for "calm and restraint" by the parties involved.
China is Sudan's largest trading partner, while Sudan is China's third-largest trading partner in Africa. According to the Chinese foreign ministry, trade between the two countries reached $8.63 billion in 2010, an increase of 35.1% compared to the previous year.
The close bilateral cooperation is mainly driven by oil exports from Sudan, which is among the top oil suppliers for China.
The Chinese Commerce Ministry on Monday urged Chinese companies operating in Sunday to "closely monitor changes in the country's security situation and take stronger precautions to ensure the safety of lives and property," Xinhua reported.