Efforts to trace contacts in the Democratic Republic of Congo (DRC) to try to contain the country's Ebola outbreak have improved but are below target, the World Health Organization (WHO) said on Tuesday.

There have been 550 confirmed cases of Ebola, including 101 deaths, according to the WHO's latest figures, as well as 94 suspected cases. 

The outbreak of the Bundibugyo strain of Ebola was announced on May 15, though officials have since said it went undetected for weeks, complicating efforts to bring it under control.

"We have reached 62% of contacts, but our target is 90-95%," Dr Abdi Mahamud from the WHO told reporters in Geneva via video link from Bunia in the DRC.

"It is slow steady progress, but we have not reached where we want to be," he said, pointing to the importance of healthcare workers building trust on the ground to identify and refer cases, and help with contact tracing.

"With the ramp up of contact tracing and community workers, we hope to achieve that target in the coming weeks," he added.

Mistrust and resistance ‌have ⁠hampered the response, with attacks on burial teams and treatment centres reported.

The latest attack occurred on Sunday when two people were seriously injured and two vehicles damaged when a burial team was targeted at the Nyamurongo cemetery in Bunia, a source familiar with the government response said.

Separately, the Africa Centers for Disease Control and Prevention said in a release on Tuesday that contact tracing was uneven - with 78% reached in Bunia but 0% in some health zones.