Tropical storm Sonamu is expected to affect Malaysian east coast states – Kelantan, Terengganu and Pahang.

National Security Council secretary Datuk Mohamed Thajudeen Abdul Wahab advised residents in the three states to be on alert.

He said the storm, developing from the Philippines and blowing across the South China Sea, was bringing winds of 90kph as of yesterday but would be reduced to 40kph from 45kph when it reaches Kelantan, Terengganu and certain parts of Pahang.

“Although the storm will be reduced to a tropical depression, there will be strong winds, rough seas and heavy rainfall,” he said.

All residents and fishermen in those states have been advised to stay away from the sea.

"Those in flood-prone areas should be alert for warnings of heavy rain and should make advance preparations for the possibility of floods," said Mohamed Thajudeen.

These conditions are expected to continue until Friday.