A cargo ship carrying relief supplies for more than 1,000 cyclone victims in Myanmar has sunk.

International Red Cross spokesman Michael Annear called the accident a big blow to the already slow relief work.

The IFRC says the boat was traveling from Yangon to Mawlamyinegyun when it hit a submerged tree trunk and sank early Sunday.

The crew members, including four staff from the Myanmar Red Cross, managed to get to safety.

Though international aid has started to trickle in, almost all foreign relief workers have been barred entry into the isolated nation. The junta says it wants to hand out all donated supplies on its own.