Israel arrested 23 Hamas members in the occupied West Bank on Monday, some of them lawmakers, according to the group and the Israeli army.
Hamas said in a statement that the three lawmakers - Ahmed Attoun, Hatem Qafisha and Mohammed al-Talhad - had been detained in the early hours of the morning, as well as several local Hamas leaders.
"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."
An Israeli military spokeswoman 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.
"Twenty-five Palestinians were arrested, 23 of them belonged to Hamas," she said.
Hanan Ashrawi, a senior Palestinian official in the West Bank, condemned the arrests, describing them as "deliberate Israeli plans to destabilise the internal situation, interfere in Palestinian institutions... and deal a blow to national reconciliation," according to the AFP news agency.
Hamas, which Israel, the United States and the European Union consider a terrorist organisation, won the last Palestinian parliamentary election, in 2006.
In 2007, after a unity government collapsed, it seized control of the Gaza Strip from Western-backed President Mahmoud Abbas's Fatah movement.
Egyptian efforts to broker a reconciliation deal between Hamas and Fatah, which holds sway in the West Bank, have so far been unsuccessful.