Israel arrested a lawmaker from the Palestinian Islamist movement Hamas, Palestinian security forces said.
Fadel Hamdan was detained on Sunday night after around two dozen Israeli army jeeps ringed the area of Ramallah where he was based, security forces said, without elaborating.
In the early hours on Sunday, Israeli forces had also arrested Aziz Dweik, the Hamas speaker of the Palestinian parliament.
Israeli troops detained 64 other leading Hamas figures, including eight ministers and 26 lawmakers, on June 29.
The ruling Islamist Hamas movement is considered to be a terrorist group by Israel and the West.
The Israeli crackdown, which has also involved large military incursions in Palestinian areas, began on June 28, three days after Palestinian militants from Gaza killed two soldiers and captured a third in a cross-border raid.
The military says it aims to recover the soldier and to stop Palestinian militants from firing rockets into Israeli territory.
Following the capture of the Israeli soldier, the Jewish state embarked on a campaign to strangle Hamas, whose armed wing was one of the three militant groups that took part in the abduction.