The Palestinian sources said arrests took place in the areas of Qalqilyah, Nablus, Hebron and Ramallah. They said 13 people were arrested after the Israeli security forces carried a thorough search in their houses.

Israeli security sources said the raids targeted "wanted Palestinian terrorists."

The sources added that they were taken to unknown locations for questioning by the Israeli intelligence service Shin Bet.

The Israeli defense establishment says the almost daily arrest campaigns in Palestinian territories are part of its war against Palestinian armed groups.

The Palestinian Authority says the Israeli raids hinder its security forces from tightening their grip on the Palestinian territories.

Israel does not allow the PA to have any security role in specific areas of the West Bank that the 1993 Oslo peace agreement  classified as C areas.

According to the recent Palestinian statistics, Israel is holding in its 25 prisons around 7,000 Palestinians and Arabs, many of them for more than 25 years.

Meanwhile, the Israeli police arrested 33 illegal Palestinian workers in a nature reserve in Ashdod. The police said the Palestinians were found residing in shacks inside the reserve and were taken for questioning.

The arrest of the workers came a day after Israeli Prime Minister Benjamin Netanyahu gave his support for a proposal to increase the number of Palestinian workers allowed to work in Israel.

According to the plan, 4,000 Palestinians will be given permits to work in construction and 1,250 in agriculture, making total of 5,250 workers, all West Bank residents.