The Lebanese army announced Sunday the arrest of Sudanese citizens near the border with Israel and was questioning them.
The announcement came hours after the Israeli military said it detained the five on suspicion they were trying to infiltrate the heavily-guarded border.
Israeli media said the five were job seekers who were returned to Lebanon in coordination with the United Nations.
A spokesman for the UN peacekeeping force in Lebanon said they are looking into the case with the parties without elaborating.
The incident comes as the Lebanon-Israel border has witnessed tensions in recent weeks between Israel and the Iran-backed armed Hezbollah party.
Last month, an Israeli drone fired two missiles near an SUV carrying Hezbollah members in Syria, close to the border with Lebanon. No one was hurt in the attack.
Two days after the drone attack, Israel accused Hezbollah of “provocative” activity, including multiple attempts to breach the border along the Lebanese-Israeli frontier, and said it would complain to the UN Security Council.
Israel and Hezbollah fought a bruising, 34-day war in 2006 that ended in a stalemate. Despite their deep hostility, they have largely refrained from direct fighting for the past 14 years.