An Israeli soldier points during clashes with stone throwing Palestinians in the West Bank village of Burin, south of Nablus Feb. 2, 2013.
An Israeli military spokeswoman said 25 Palestinians were arrested overnight, with 23 belonging to the Islamist group.
She would not confirm whether Hamas lawmakers had been arrested and did not provide any of the men's names or say why they had been detained.
Hamas said in a statement that the three Hamas lawmakers -- Ahmed Attoun in al-Bireh, Hatem Qafisha in Hebron and Mohammed al-Tal in al-Dhahiriyya -- had been detained in the early hours of the morning.
"It is a criminal act that will not succeed in stopping their struggle," the statement said. "We in the Hamas movement strongly condemn the campaign of arbitrary arrests that took in dozens of Hamas leaders."
Twelve other Hamas officials were seized in the raids overnight Saturday, as well as several Palestinians not holding a political position, according to local sources.
In Hebron, forces detained Dr Zein Addin Shabanah from Hebron city and Sheikh Samir Buheis from Yatta.
In Ramallah, Israeli troops arrested Sheikh Falah Nada from Al-Bireh and Adnan al-Husary was seized in Tulkarem. In Qalqiliya, Riyad Walweel and Sheikh Muhsin al-Hardan were detained.
Five other Hamas officials were seized in the Nablus district. They were identified as Adnan Asfour, Bahaa Yaish, and Bakr Said Bilal from Nablus city, and Omar al-Jibrini from Balata refugee camp and Mahmoud Saqr Asida from Tal village.
Meanwhile, locals identified seven other Palestinians detained overnight. They were named as Fadi al-Amouri from Tulkarem, Mamoon Muhammad Zawahira from Doha in Bethlehem. In the Nablus village of Qaryut, Jihad Salah Addin Badawi, Nidal Salah Addin Badawi, Mujalli Zuheir Issa, Qahir Ahmad Muammar, and Shakir Ahmad Mousa were all detained.
Israel holds 4,743 Palestinians in its prisons, including 178 held without charge, according to latest figures from prisoners group Addameer.
The Palestinian Authority says 15 MPs are currently detained in Israel jails.
Impediment to reconciliation
Gaza's minister of prisoners' affairs Atallah Abu al-Sabh warned that the detentions could impede the ongoing efforts to achieve reconciliation between rival Palestinian factions Hamas and Fatah.
At a Gaza City news conference the official laid some blame at the Fatah-led authorities in the West Bank.
"These detentions wouldn't have been made without high-level security coordination," Abu al-Sabh said, referring to coordination between Israeli forces and the Palestinian Authority's security services.
Meanwhile, PLO official Hanan Ashrawi said the arrests were an Israeli intrusion into internal Palestinian politics.
"It is apparent the Israeli government is implementing a policy of intimidation and power politics to meddle in Palestinian domestic affairs and to undermine reconciliation efforts," she said in a statement.
She urged Arab, European and international parliaments to urge Israel to respect human rights, including the immunity of democratically elected officials, saying "Israel is not above the law."