Image copyright AFP Image caption Toyota's Prius was the first mass-produced hybrid vehicle

Toyota is recalling 1.9 million of its top-selling Prius hybrid cars because of a software fault that may cause the vehicle to slow down suddenly.

The world's biggest carmaker said it had identified more than 400 reports of the problem, with the bulk of them occurring in Japan and North America.

No accidents or injuries have been reported over the defect, Toyota said.

The recall comes weeks after Toyota halted the sale of some car models in the US over problematic seat heaters.

It also deals a blow to the Japanese carmaker, which has seen its reputation suffer following a series of mass recalls in recent years.

The latest recall affects the current generation Prius sedans made since March 2009.

The Prius was first released in 1997 and is one of the most popular hybrid vehicles on the market.

The new software problem can set off warning lights, and will "probably cause the vehicle to enter a failsafe" mode, which will see the car's driving power reduced.

"In limited cases, the hybrid system might shut down and the vehicle will stop, perhaps while being driven," Toyota said.

In 2010, Toyota's share price was hit after more than 10 million of its vehicles were recalled over unintended acceleration issues.

Despite its problems, Toyota is forecasting a record profit for this year because of the effects of the weaker Japanese currency, which makes its cars cheaper abroad.

Last year, it was the top-selling global carmaker, with worldwide deliveries rising 2.4% to nearly 10 million vehicles.