More dikes than expected need to be strengthened along the Maas river in Limburg, according to a report presented on Friday.

An investigation in 2010 by the provincial water authority concluded that 117 kilometres of the Limburg dikes did not conform to new standards brought in following floods in 1993 and 1995 and these would be strengthened.

However, a new investigation shows that an extra 28 kilometres and possibly 48 kilometres of dikes are not strong enough, reports news agency ANP.

The water authority does say in its report that the dikes are safe.

Limburg has a total of 176 kilometres of dikes along the Maas river.