A top European human rights official says asylum-seekers in Hungary run "considerable risk" of having their rights violated because of recent changes to asylum law and practices.

Nils Muiznieks, human rights commissioner for the Council of Europe, issued a statement Wednesday related to complaints against Austria for transferring migrants to Hungary according to Europe's so-called Dublin asylum rules, despite concerns about Hungarian abuses.

Muiznieks visited Hungary in late November, and said "a considerable proportion" of asylum-seekers sent to Hungary were put in detention and that they "do not, as a rule, have their asylum applications examined on the merits."

Nearly 400,000 migrants fleeing war and poverty entered Hungary last year, and the government has tried to stem the flow, notably with border fences.