Two more ATMs were blown up in Sydney overnight, taking the tally of attacks to five nights in the past week.

The blasts were the latest in a string of gas attacks on ATMs in New South Wales, Victoria, Queensland and the ACT.

Police say they were called to one of the explosions about 2:00am (AEDT) at a shopping centre at West Pennant Hills, in north-west Sydney.

The ATM at the Coonara Avenue centre remained mostly intact but the stairwell it was housed in was badly damaged.

About half an hour later, police say an ATM and several neighbouring shops were damaged in an explosion near a shopping centre in Evans Road at Telopea.

Debris from the blast was strewn across the road.

Police say cash was taken from the second ATM but not from the first.

They say witnesses have told them several men fled the scene at Telopea in a dark vehicle.

The New South Wales Government is offering a $100,000 reward for information leading to a conviction over the robberies, on top of $50,000 on offer from the Australian Banking Association.

Anyone with information about the blasts is urged to call Crime Stoppers on 1800 333 000.