Seven more people ─ including three Chinese nationals ─ were arrested on Tuesday as the Federal Investigation Agency (FIA) continues its crackdown on a gang allegedly involved in the trafficking of women to China for prostitution.

The FIA identified the arrested suspects as Song Chuaoyang (ring leader), Rafique Hussain (translator and manager), Sajid (facilitator), Guyong Da, Saima Mustafa, Fusing Bu and Saba Jahangir.

The raid — which was conducted under the supervision of FIA Anti-Human Trafficking Cell Rawalpindi's Deputy Director Kamran Ali — took place after two women, Tayyaba Gul and Beenish Rasheed, appeared before the director general of FIA to tip the agency off regarding the gang's activities.

The arrests come a week after Human Rights Watch said Pakistan should be alarmed by recent reports of trafficking of women and girls to China. It said the allegations were disturbingly similar to the pattern of trafficking of "brides" to China from at least five other Asian countries.

The Chinese embassy in Islamabad has also raised the alarm over illegal, cross-border matchmaking services that are often a front for human trafficking. Last month, it issued a statement condemning reports of the existence of bureaus orchestrating illegal marriages. "China is working together with the Pakistani government and law enforcement agencies to track these illegal marriage centres," the statement said.

The embassy has denied reports that the women were being trafficked for the sale of their organs as "misleading and groundless".

Jameel Ahmad, a top FIA official, told Reuters that the agency had busted the gang after it received information about the increasing smuggling of Pakistani woman to China where they are thrown into prostitution. He said several gangs were believed to be operating, mainly targeting members of the Christian community.

Ahmad said the police raid he led on a wedding ceremony last week in Faisalabad was a major breakthrough in the investigation. He said a man and a woman from China and a fake priest were arrested at the ceremony where a Christian girl was to be married.

"The gang members confessed that they have sent at least 36 Pakistani girls to China where they are being used for prostitution," he said. The majority were Christians from different districts in Punjab, he said.

According to the agency, more arrests will take place in connection with the case and further investigations are underway. The arrested individuals have been nominated in FIA enquiry number 352/19.

This is not the first such case to come to light. On Monday, the FIA's Lahore wing had arrested eight Chinese nationals from Lahore on suspicions of being involved in human trafficking, and last week, the FIA arrested four people, including two Chinese nationals, during the raid in Faisalabad.

Earlier this year, a Chinese national was apprehended at the Islamabad International Airport for allegedly trafficking a Pakistani woman who claims to have been 'sold' by her parents.