Rival Lebanese leaders had urged calm on Wednesday after the two were kidnapped on Monday as sectarian tensions in Lebanon rise.
Meanwhile, Lebanese media had reported that the two were kidnapped by members of a Shia clan who had vowed to avenge the killing of their relative in clashes at a Beirut university in January.
The Shia Shamas clan, named by the media, condemned the kidnapping and distanced itself from the abduction in a statement on Wednesday.
Sporadic violence between the mainly Sunni, Druze and Christian ruling coalition and mainly Shia and Christian opposition have killed 10 people since the opposition launched a street campaign to topple the government last year.
The political crisis, Lebanon's worst since the 1975-1990 civil war, has at times threatened to spill into Sunni-Shia strife as sectarian tensions run high.