The Washington DC-based group said that August 14 is a black day for Muhajirs, Balochs and other ethnic and religious minorities of Pakistan.
Muhajirs are Urdu-speaking people who migrated from India during partition.
"Pakistan Army and Paramilitary Rangers have killed more than 22,000 innocent Muhajirs in brutal military operations in Karachi and other urban centers of Sindh in the last few years," WMC alleged, claiming that the fundamental rights, political space and freedom of Muhajirs have been curtailed.