It is still not clear why the foreigners were taken captive in the northern West Bank town.
Reuters reports the nationalities of the men are Irish, British and American.
Palestinian security forces combed the area in search of the captors and their captives, Aljazeera's correspondent said.
In mid-July, a spate of kidnappings, which targeted Palestinian security officials and French aid workers, triggered a series of resignations and fears of a breakdown of authority.
The workers were also released within a few hours.
On 16 July, members of the Jenin Martyrs' Brigades briefly captured the police chief in the occupied Gaza Strip and West Bank, Ghazi al-Jabali.
He was released only after securing assurances he would be replaced.
The kidnappings set off intense discussions between Palestinian President Yasir Arafat and Prime Minister Ahmad Quraya, who resigned but later agreed to stay on.
As Palestinian factions demanded political reform, Arafat's National Security Council declared a state of emergency and sent troops to protect government buildings and officials from harm.