Many Germans have been hit by a computer bug linked to the year 2010 that has rendered their credit cards useless, the ZKA banking commission said on Monday.

Cards issued by "many credit institutions" have run up against "a software error during the passage to the year 2010" that does not however cause security problems, the commission said in a statement.

Clients at two of the biggest German retail banks, Postbank and Commerzbank, have been affected in particular but ZKA could not say how many people in all were faced with problems.

An AFP journalist noted that cards hit by the bug could not be used to either withdraw money from ATMs or to pay for items in stores.

ZKA said the problem should be resolved by Tuesday.