According to the local security officials, the 20 passengers were among 43 people kidnapped from a highway in Greshk district on Tuesday.
The 215th Maiwand Corps of the Afghan National Army (ANA) forces said at least 18 of the passengers were released shortly after they were kidnapped and 20 others were released later on that day.
The source further added that the Taliban militants are still holding 5 passengers as hostage in their custody and efforts are underway for their release.
The Taliban militants have stepped up hostage takings across the country during the recent weeks as the group claim they abduct security personnel and government officials traveling in the highways.
Numerous kidnapping incidents have taken place in northern Afghanistan following a major kidnapping incident that took place late last month in northern Kunduz province.
At least 185 passengers were kidnapped as they were traveling on the main highway in Kunduz last month but majority of them were released after they were interrogated.
In the meantime, Taliban said Tuesday that they are not kidnapping the passengers and claimed that the passengers are stopped on the highways only to interrogate as part of their normal process to find out the security personnel.