"We have a very big problem here, " Calumpit Mayor James de Jesus told ABS-CBN TV network.

BBC: Philippines recovers after Typhoons Nesat and Nalgae

The climbers who died were struck by huge rocks, guide Kenneth Jesalva told ABS-CBN TV network by cellphone from a camp near the crater.

NPR: Philippine Volcano Spews Rocks, Killing 5 Climbers

Provincial disaster official Raul Agustin told ABS-CBN television that marooned flood victims were often reluctant to leave for fear their homes would be looted.

BBC: Philippines recovers after Typhoons Nesat and Nalgae