Dhaka, Dec. 6 -- Indonesia's military stepped up its relief efforts in three provinces on Sumatra island that have been devastated by deadly floods and landslides, and the country's vice president apologised for shortcomings in the response to last week's disaster.

The military has erected at least 10 portable bridges, called "Bailey bridges", in Aceh, North Sumatra and West Sumatra provinces to help with the distribution of food and aid supplies to isolated residents, Major General Freddy Ardianzah told reporters on Friday.

"The construction of these bridges is crucial to distribute logistics. Some of the roads are still blocked so the aid is yet to reach those affected by the disaster," he said.

Ardianzah said the military was also dep...