AlHijjah 05, 1436, September 19, 2015, SPA -- Bulgaria's security forces have detained 137 foreigners in the capital Sofia in a sweep aimed at combating illegal migration, the country's latest effort to tackle the migrant crisis challenging the Balkans region, Reuters reported. The migrants, who claimed they were from Syria, were detained following an operation by the state security agency (SANS), gendarmes and border police on Friday night, the interior ministry said in a statement on Saturday. The ministry said the foreigners, who were detained after checks in hostels and small hotels in central Sofia, would be questioned. It is yet to be determined how they entered the country and whether they should be granted refugee status. Earlier this month, Bulgaria detained 125 foreigners in Sofia for illegally crossing into the country without submitting requests for asylum.