The two had returned from Delhi on May 4.
Sirmaur deputy commissioner RK Pruthi said the two were quarantined after they had returned to Hari Om Colony in Paonta Sahib on May 4 and their samples were randomly taken for testing on May 12.
Both of them were asymptomatic.
The two tested positive for COVID-19 at Central Research Institute, Kasauli, on Wednesday night, Special Secretary, Health, Nipun Jindal said.
A total of 706 people have returned to Sirmaur district from various red zones, Pruthi said, adding that samples of 541 people out of them had been taken and the two tested positive.
With this, the number of positive cases in Sirmaur district has risen to four. Two people have been cured in the district.
The total number of COVID-19 cases in the state has now climbed to 70 and three people have died due to the virus so far.
Thirty-nine people in the state have so far recovered from the infection.
Himachal Pradesh now has 28 active COVID-19 cases -- 11 in Kangra, six in Chamba, four in Hamirpur, two each in Sirmaur, Bilaspur and one each in Mandi, Una and Shimla. DJI DVDV