Less than 10 percent of requests to send back migrants from EU member states were granted by Bulgaria between July 2015 and June 2016.

Some 449 migrants were received by Bulgaria, out of 5943 requests filed by the other EU countries, according to daily newspaper Sega.

The figures come a day after a Syrian man, whom Bulgaria had refused to take back from Germany, blew himself up in Ansbach, Bavaria, injuring 15 people (while initial data had put the number at 12).

Petya Parvanova, who heads the State Agency for Refugees (DAB), is quoted as saying it was the humanitarian status, granted to the man by Bulgarian authorities in 2013, that prevented them from taking him back.

Parvanova has also told NOVA TV station that the security and counter-intelligence agencies had not considered him a "national security threat" or "prone to radicalization" during the interviews every asylum candidate holds upon filing a request in Bulgaria.

Humanitarian status holders in Bulgaria have the rights of foreign nationals with permanent residency documents.

The 27-year-old Syrian, who has not been officially named by German authorities yet, was denied status twice in the Western European country, officials say.

Prior to his arrival in Germany, he had resided for 8 months in Bulgaria.

The SITE intelligence group, a network monitoring the activity of terrorist organization, has named the man as Mohammad Daleel.