BRUSSELS — U.N. agencies are pressing the European Union to end the growing practices of denying migrants their right to apply for asylum, collectively expulsing them and using violence against people trying to enter the bloc without authorization.

Border pushbacks and collective expulsions are illegal under international refugee treaties, which allow people fearing for their safety to apply for protection. Greece and even the EU's border and coast guard agency Frontex are among those accused of pushbacks or complicity in them. They deny using such methods.

The International Organization for Migration said Wednesday that it continues to receive documented reports of human rights violations against migrants and refugees, including children, involving countries that are part of the 27-nation bloc.

"The use of excessive force and violence against civilians is unjustifiable," IOM Chief of Staff Eugenio Ambrosi said. He said the sovereignty of EU countries "including their competence to maintain the integrity of their borders must be aligned with their obligations under international law and respect the human rights and fundamental freedoms of all."

The IOM, which receives EU funds for its work in countries around the Mediterranean and North Africa, said it welcomed a series of investigations launched to get to the bottom of the pushback cases.

Late last month, the U.N. refugee agency also warned that the right to asylum is "under attack" at Europe's borders and it called on countries to investigate and stop illegal pushbacks and expulsions. 

The UNHCR said new migrant arrivals to the EU continue to decline each year, with 95,000 arrivals by sea and land last year — a decrease of 23% compared to 2019 and by one-third compared to 2018, when more than 141,000 people arrived.

Last month, Frontex announced it was ceasing work in Hungary until the nationalist government there brings its laws into line with a ruling by the EU's top court that the country is denying people entering without authorization the right to apply for asylum and unlawfully detaining them in "transit zones."

The rising number of pushback allegations comes at an embarrassing time, as the European Commission struggles to win unanimous support among EU nations for its new Pact on Migration and Asylum, which is meant to revamp the bloc's dysfunctional asylum laws.