Among those who tested positive are three cancer patients, and a 13-year-old girl who recently underwent heart surgery in Mumbai. The other three are their attendants.
"Seven patients and attendants who came from Mumbai and now in quarantine tested positive," the minister tweeted.
Six buses carrying 137 passengers, mostly cancer patients and their attendants, arrived here from Mumbai late on Tuesday and they were quarantined at a hotel.
At present, there are 44 active cases in the state, one migrated to Bihar and two died. Total 39 people have recovered so far and discharged from the hospital.
Assam has reported 24 cases so far this week with 15 on Wednesday itself.
The Kamrup (Metro) district administration has added several areas in the city to the list of containment zones. This includes parts of the commercial hub of Fancy Bazaar, the area around the Panbazaar Higher Secondary School, Kumarapara, Santipur and Fatashil Ambari areas.
Earlier some areas around Guwahati Medical College and Hospital, Regional Dental College, Employees Colony of B Barooah Cancer Hospital and Amiyonagar in Chandmari were declared containment after five cases were reported last week.
Assam has so far tested 23,455 samples in seven laboratories of the state.
Meanwhile, a train from Delhi arrived at Dibrugarh on Thursday morning and 400 passengers deboarded, including those from Tinsukia, Sivasagar, Charaideo, Lakhimpur and Dhemaji districts and Arunachal Pradesh, officials said.
Four members of a family, including two children, were found to be having high fever. They were isolated at the Assam Medical College in Dibrugarh and their samples were collected for testing.
Teams from the district administrations of Dibrugarh, Tinsukia, Sivasagar, Charaideo, Dhemaji, Lakhimpur as well as officials from Arunachal Pradesh received the passengers from their areas and after preliminary screening took them to the quarantine centres at the respective districts.
In Guwahati, 130 passengers deboarded from the same train on Tuesday night and out of them, 51 people who are residents of the city were brought to the Sarusajai Stadium for screening and the remaining were sent to their respective districts for screening and quarantine.
Assam has adopted a three-tier quarantine system with those without symptoms and negative reports to be sent for home quarantine, where the home will be declared a containment zone and all family members will also have to be quarantined.
Those having symptoms but negative reports will have to remain in 14 days institutional/paid quarantine while the positive cases will be sent to the hospital. DG SOM SMNSMNSMN