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 deploying mobile reverse osmosis systems, which make polluted water safe to drink, and would continue to make airdrops of food and medications to residents still cut off from road access.

Indonesia’s death toll from last week’s cyclone and subsequent severe flooding and landslides rose to 867 people on Friday afternoon with 521 listed as missing, government data showed. The storm systems also killed about 200 people in southern Thailand and Malaysia.

Local government officials on Sumatra have been calling on the government to declare a national emergency to free up additional funds for rescue and relief efforts.

Earlier this week, President Prabowo Subianto had said the situation was improving and current arrangements were sufficient, but his deputy took a different view after visiting affected areas on Thursday.

“I apologise. You are not alone, the people of Sumatra are not alone,” Vice President Gibran Rakabuming Raka said in a statement after his visit.

“We will ensure that those in the evacuation centres receive proper care. Many have complained about issues with schools and housing, we will assist you with that. Thank you, and once again, I sincerely apologise.”