"We need food and water, but it is difficult to transport emergency aid to some neighborhoods that are cut off," said Mayor James Yap in a radio interview.
"Helicopters are required because people are very hungry."
Monday's powerful earthquake off the southern Philippines killed at least 47 people and injured nearly 700. About 30 are still missing and over 45,000 people have been forced to leave their homes.
In Sarangani province, where Glan is located, 20 deaths have been recorded. The city, which has a population of over 100,000, is still without power and mobile phone service. Ten of the city's 21 districts are completely cut off due to landslides.
