The elder brother, aged 37, was angry when the machine declined his bankcard and he started to shout at everyone in the bank before an officer asked him to leave.
However, the man went to his BMW car parked outside the bank, took an iron rod from the car and started swinging the rod when he entered inside the bank.
Muar acting police chief Supt Shahadan Jaafar said someone alerted the police which rushed a patrol unit to the bank at about 12 noon on Monday
The moment the man saw the patrol car outside the bank he and his younger brother, aged 36, decided to run away.
They sped in their BMW car towards Jalan Haji Abu but police managed to stop the car at Jalan Abdullah, he told reporters yesterday.
Supt Shahadan said both brothers were brought to the Muar police station and a urine tests showed they were under the influence of the drug syabu.
He said the elder brother was also a wanted man who was involved in drug-related case and both had been detained under remand for 14 days.