Ahmedabad, Jun 16 (PTI) ?The Gujarat Anti Terrorist Squad has questioned four persons ahead of Prime Minister Narendra Modi's visit to the state, a senior ATS official said here on Thursday.

All four were allowed to go after questioning on Wednesday, the official added, without disclosing why they were detained.

One of them is a homeopath who has a clinic in Wadi area of Vadodara, the official said.?

Another person is also a Vadodara resident, while the other two are from ?Ahmedabad and Bhavnagar, he said.

"Questioning people is a part of routine process. All of them were let go afterwards. We may call them again if needed," said the official.

Prime minister Modi is scheduled to visit Vadodara on June 18 to launch a host of government projects.?