Alarmed by the possibility that a prisoner exchange agreement with Israel will bolster Hamas's popularity among Palestinians, the Palestinian Authority has stepped up its measures against the movement's leading figures and members in the West Bank.

Over the past 48 hours, PA security forces arrested 14 Palestinians in the West Bank on suspicion of being affiliated with Hamas, sources close to the movement said on Monday.

The sources said the latest crackdown was clearly linked to reports that a prisoner exchange agreement will soon be reached between Hamas and Israel.

"The Palestinian Authority is very nervous because of the talk about a deal," the sources said. "They know that the release of hundreds of prisoners from Israeli jails would boost Hamas's popularity."

As the "forum of seven" Israeli cabinet ministers continued their deliberations in Jerusalem about the release of prisoners whom Hamas was demanding in return for St.-Sgt. Gilad Schalit, Azzam al-Ahmed, a Fatah official and close aide to PA President Mahmoud Abbas, called for an "intifada" against the Islamist movement.

Ahmed's appeal to the Palestinians reflected growing concern among the PA leadership in Ramallah over attempts by Hamas to extend its control to theWest Bank. He and other Fatah officials expressed fear that Hamas was planning to exploit the return of prisoners to their homes in the West Bank to organize anti-PA rallies in some cities, villages and refugee camps.

Hamas responded by calling for an "intifada" against the PA in the West Bank.

Yahya Musa, a top Hamas official in the Gaza Strip, urged Palestinians to launch a "popular intifada against the PA because of the suffering of the Palestinians in theWest Bank as a result of the actions of its security forces that operate under the supervision of the CIA."

A PA official in Ramallah condemned the Hamas call as an attempt to stage a coup against the "legitimate representatives of the Palestinians."

The official warned that the Palestinian security forces would take severe measures against any individual or party involved in efforts to undermine the PA.

Almost all the Hamas figures and members who were arrested in the past two days have been detained by the PA security forces in the past.

In Nablus, the PA security forces arrested ex-detainees Lafi Hijazi, Firas Musmar, Abbas Fatayer and Hasan al-Zagha.

In the nearby village of Tal, PA security officers arrested brothers Ja'far and Muaz Rihan, ex-detainees known as local leaders of Hamas. Another two Hamas supporters from the same village, Osama Ramadan and Hamed Saleh, were also taken into custody.

In Kalkilya, the PA security forces arrested three university students for allegedly being affiliated with Hamas. They were identified as Ahmed Hasan Ghanem, Muhammad Jihad Ghanem and Radwan Atiyeh.