The Israeli army said it arrested 25 Hamas members during the night in the West Bank, among them three parliamentarians, according to sources in the Islamist movement.
The army said that "overnight 25 Palestinians were arrested all over the West Bank," but did not provide details.
Sources in Hamas said "20 senior Hamas members were arrested in the West Bank, among them three parliament members." It named them as Hatem Kafisha and Mohammad Al-Tal, arrested in Hebron, and Ahmad Atoun, detained in Ramallah.
Hamas has 74 members in the 132-seat Palestinian Authority Legislative Council, which is based in Ramallah. The latest arrests bring to 12 the number of Hamas lawmakers being held by Israel.
Security sources have told AFP that Israel plans to step up arrests of suspected militants in the West Bank to prevent a rising tide of low-intensity conflict and civil unrest from turning into an uprising.
The crackdown comes amid an increase in Palestinian unrest which Israel ties to fallout from the eight-day battle between Israel and Palestinian militants in the Gaza Strip in November.