The number of suspects detained in Turkey in a major police operation against the Islamic State group over the weekend has increased to nearly 750, authorities said Monday.

Anti-terrorism police launched the security operation against people with alleged links to ISIS early Sunday, conducting simultaneous raids in 29 provinces, including Istanbul, Ankara and the border provinces of Gaziantep and Sanliurfa. The state-run Anadolu Agency said that 440 people, including foreign nationals, were detained.

The Interior Ministry released a statement Monday saying that a total of 748 people have been detained in the police sweep. It didn't provide details or give a breakdown of the foreigners captured in the operation.

Anadolu said that police seized ISIS documents, digital material and six firearms during the raids.

Anadolu, citing police sources, said that the ISIS was "searching" for ways to carry out a "sensational attack" in Turkey, and was actively engaged in propaganda in order to recruit fighters. It said that the raids targeted suspects that were believed to be in contact with ISIS operatives in "conflict" zones.

Turkey has suffered dozens of deadly attacks linked to ISIS or Kurdish militants, and has been stepping up its anti-terrorism efforts.

ISIS, which took responsibility for a New Year's mass shooting at an Istanbul nightclub that killed 39 people, claims to have multiple cells in Turkey.

The accused perpetrator of the nightclub attack, an Uzbek national who reportedly trained in Afghanistan, was detained in Istanbul about two weeks after the assault.

Officials have said they believed his questioning would lead to valuable information about the ISIS operations and cells inside Turkey, but it wasn't immediately known if the major raid was in any way linked to his arrest.