Türkiye and the United States are cooperating to curb a Daesh terrorist group-linked human smuggling network, the U.S. Treasury Department said Friday.

After a probe closely coordinated with Ankara, Washington imposed sanctions on four individuals, three of whom were involved in the network, it said in a statement.

"As a result of this close cooperation, (Turkey) is concurrently taking its own domestic action against this network," it said. The statement did not say how long the group had been operating or how many people it had smuggled.

In May, Turkish authorities said they had detained 41 people suspected of having ties to Daesh in operations across 12 provinces.

Türkiye has ramped up operations against Daesh since the terrorist group attacked an Italian church in Istanbul in late January, killing one man during Sunday Mass.

Daesh operates a so-called Khorasan Province (Daesh-K) network in Türkiye, which looks for new "methods" and recruits more foreign members for its activities after constant counterterrorism operations became a "challenge," security sources say.

The National Intelligence Organization (MIT) thwarted the terrorist group's efforts for recruitment, obtaining funds and logistics support after its latest operation in the aftermath of the church shooting.

Daesh remains the second biggest threat of terrorism for Türkiye, which faces security risks from multiple terrorist groups and was one of the first countries to declare it as a terrorist group in 2013.

In December last year, Turkish security forces detained 32 suspects over alleged links with Daesh, who were planning attacks on churches and synagogues, as well as the Iraqi Embassy.

Terrorists from Daesh and other groups, such as the PKK and its Syrian wing, the YPG, rely on a network of members and supporters in Türkiye.

In response, Ankara has been conducting pinpoint operations and freezing assets to eliminate the terrorist groups at their roots. Türkiye deported 9,000 foreign terrorist fighters, mainly from Daesh, from 102 different nationalities, of which 1,168 are from the U.S. or European Union member countries, since 2011.

Turkish airstrikes also target hideouts of Daesh, as well as PKK, in northern Iraq and Syria near the Turkish border.