Of these 20 patients were recorded in Da Nang, seven in Hanoi, two in Bac Giang and one in Phu Tho.
The new cases took the total number of domestic cases confirmed Wednesday to 82, with 18 recoveries.
Deputy Prime Minister Vu Duc Dam on Wednesday demanded authorities of Da Nang City and the northern provinces of Bac Ninh and Bac Giang to strictly prevent the contagion of Covid-19 in industrial parks. Such cases will disrupt the manufacturing and supply chains and will severely hurt the economy, he added.
Since April 27 Vietnam has confirmed 611 community transmissions in 26 localities. Hanoi leads the list 162 cases,99 of which are in two hospitals, followed by Bac Ninh with 124, Bac Giang with 81 and Vinh Phuc with 73.
The national Covid-19 tally stands at 3,623, with 2,636 recoveries.
More than 887,700 people have been vaccinated to date, 20,732 getting their second shots Tuesday.