The fate of 29 Chinese construction workers kidnapped in Sudan is unclear after Chinese officials were quoted casting doubts on reports that some had been freed.
Chinese state news agency Xinhua quoted embassy officials in Khartoum as saying all the workers were still missing.
Earlier, Sudan's army said that 14 had been "liberated".
The group was seized by rebels in South Kordofan state, near the border with South Sudan on Saturday.
A spokesman from the Sudan People's Liberation Movement-North (SPLM-N) rebels told the AFP news agency on Sunday that the workers were caught in crossfire with the army.
He said they were captured together with nine Sudanese soldiers after the SPLM-N attacked and destroyed a Sudanese military convoy in the area.
However, Wang Zhiping, a senior executive of the Power Construction Corporation that employed the workers, told Xinhua the rebels had attacked the workers.
Sudan's army said the rebels had attacked the compound of the Chinese construction company and captured 70 civilians.
"Most of them are Chinese. They are targeting civilians," army spokesman Sawarmi Khaled Saad told Reuters news agency.
South Kordofan governor Ahmed Mohamed Haroun had said 14 workers had been freed and were in good health.
But a later Xinhua report said 29 Chinese nationals remained missing.
The report said 17 other Chinese had been rescued from the facility, but it appears they were not among the people who had been captured.
South Kordofan is one of three areas hit by conflict since South Sudan became independent from Sudan in July.
Abyei and Blue Nile along with South Kordofan lie along the loosely demarcated border between Sudan and South Sudan.
China, which is the biggest buyer of oil from Sudan, is a key trading partner of the country.
The SPLM-N fought alongside former rebels who led South Sudan to independence in July 2011 - the two groups deny charges from Khartoum that they are still working together.
Sudan's government has denies accusations from human rights that is carrying out a campaign of ethnic cleansing against the Nuba community seen as supporting the SPLM-N.
Last week, Sudan also denied that it had bombed refugees who had fled the conflict into South Sudan.