A Burmese exile group says thousands of people are in urgent need of international assistance in northern Burma, where ethnic Kachin rebels have been under attack by government forces since early last month.

The Kachin Women's Association Thailand said Wednesday that more than 16,000 refugees are sheltering in makeshift camps near the Chinese border. It said villagers suspected of supporting the rebels have been killed and tortured and that it has documented 32 cases of systematic rape.

The group said the refugees are cut off from assistance, while Chinese authorities are refusing to let them seek safety in China. It said local Kachin networks and churches are unable to address the refugees' needs and that international help is urgently needed.

The association said the refugees will also require long-term assistance because they have been forced to abandon their rice fields.

Fighting between the 8,000-man Kachin Independence Army and the government began in June when Burmese forces marched on Kachin areas near where China is building two hydroelectric dams. Kachin news reports say the rebels have sabotaged bridges and railway lines to slow the Burmese advance.

It is almost impossible to confirm reports about the fighting. Burma's border areas are largely off limits to foreigners and journalists.

The Kachin Independence Army, like other ethnic militias in Burma, signed a cease-fire with the central government almost two decades ago. But those agreements began to break down in 2009, when Burma demanded that the militias come under central authority and serve as part of a national border guard.