Sweden's Financial Supervisory Authority on Tuesday fined the country's two biggest banks for negligence in their work to prevent money laundering and terror financing.

The FSA fined Nordea 50 million kronor (5.4 million euros, $6.0 million), and Handelsbanken 35 million kronor.

The agency was scathing in its criticism of Nordea.

"Nordea has not complied with the money laundering rules for several years. The bank has not evaluated the risks associated with various customer groups and in some cases has been unaware of whether they actually have high risk customers," the FSA said in a statement.

"This means that if people have tried to launder money or finance terrorism that they could have done so without Nordea having been able to detect this. This is very serious," it said.

The deficiencies at Handelsbanken were considered less serious, the FSA said. While it handed down a warning on Nordea, it gave Handelsbanken a "remark".

"Handelsbanken has not complied with the money laundering rules in several areas," it said.

"These deficiencies are significant and mean that Handelsbanken ran a high risk of being used by people to launder money or finance terrorism," it added.

According to the FSA, more than 100 billion kronor (10.8 billion euros, $12 billion) are laundered in Sweden every year.