Updated

Hungary has begun building a second fence on its border with Serbia to stop migrants from freely entering the country.

The government spokesman's office confirmed a report published Monday in pro-government newspaper Magyar Idok.

Hungary built a barrier along the length of its borders with Serbia and Croatia in 2015. The government says the second fence is needed because it expects a surge of migrants to reach its borders this year.

Human rights advocates have been strongly critical of Hungary's migration policies, including measures that would lock asylum-seekers in border camps made of shipping containers while their cases are decided.

In a letter to the European Commission, the Hungarian Helsinki Committee and Human Rights Watch said the planned legal changes in Hungary would go against EU rules by, for example, "severely" limiting refugees' access to asylum.