TAIPEI (Reuters) - At least three major Taiwan banks have suspended cash withdrawal services at their Automated Teller Machines after First Bank reported T$70 million ($2.2 million) was stolen from its ATMs.

Two individuals withdrew cash from First Bank's ATMs but were not seen on close-circuit TV camera to be physically operating the machines, First Bank said in a statement. The bank discovered the theft on Monday.

The theft took place at ATMs manufactured by Wincor Nixdorf, First Bank's Executive Vice President Yeh Chung-huei said, adding it has about 300 of such ATMs. First Bank is the banking arm of First Financial Holding.

"We reported to the police yesterday...We've not decided when to resume the service of those machines," Yeh said.

Initial investigations by police showed the theft was due to malware, he said.

As a precaution, Chang Hwa Bank confirmed to Reuters it had halted operations at some ATMs made by the German company, and state-owned Chunghwa Post Co said in a statement it had also suspended some ATMs.

Calls made after hours to Wincor Nixdorf's Taiwan office went unanswered on Tuesday.

An official at the Financial Supervisory Commission, Taiwan's top banking and market regulator, said 21 Taiwanese banks own 4,990 ATMs made by the Germany company. It was not clear how many ATMs across the island had halted cash withdrawal operations as a precaution or have been affected by the malware.

(Reporting by Faith Hung; Editing by Jacqueline Wong)