The disappearance of the youths, some of whom are medicos and engineering graduates, came to the fore after their relatives brought the matter before the authorities.
Some families from Kasargod and Palakkad districts had approached Kasargod MP P Karunakaran and expressed fear that their children were missing for the past one month and they have no contact with them.
The Chief Minister termed the issue as "very serious" and ordered an urgent probe. "This is a very serious issue. This has to be examined," he told reporters in Kochi.
When contacted, DGP Loknath Behara said on the basis of information provided by the families, police has started investigation.
"We do not know if children and women are part of the group. But they (families) say that some women are in the group. We also do not have any confirmation so far that the missing youths have joined the IS. But we have started investigation", Behara told PTI.
Of the 17 persons, 11 hail from Padna and Thrikaripur in the northernmost Kasaragod district while the others hailed from Palakkad. There are at least three women including an eight month pregnant woman.
Meanwhile, families of two more youths filed a complaint before Chandera police in Kasaragod about their disappearance.
The two youths had called up to say they would return during Eid. But they have not returned and their relatives have filed a complaint, police said.
However, the complaint does not state that they are suspecting IS links.
All the missing persons are below the age of 30 and highly qualified, including medicos and engineering graduates, family members said.