HEBRON, West Bank (AP) _ Two Muslim militants suspected of plotting suicide attacks have gone underground and are trying to sneak into Israel, Palestinian security officials said today.

Palestinian police have set up roadblocks in areas under their control to try to find the two, and have passed on warnings to Israeli intelligence, said Jihad Abu Ammar, a Palestinian security official in the West Bank town of Hebron.

The warnings came a day after Prime Minister Shimon Peres of Israel cited intelligence reports that Islamic militants would try to carry out a suicide attack on Israel's election day, May 29.

Peres in the past has accused Iran of ordering its followers in the region _ including the Palestinian Hamas and Islamic Jihad groups _ to step up terror attacks to topple his government and wreck Mideast peacemaking.

Peres is being challenged by opposition leader Benjamin Netanyahu, who has said that, if elected, he would take a harder line than Peres and make fewer concessions to the Arabs.

Peres maintains a narrow lead over Netanyahu in opinion polls, but a terror attack could wipe that out: The prime minister saw his much wider lead evaporate after Palestinian militants carried out four suicide bombings in Israel two months ago, killing themselves and 59 others.

The two suspected militants missing from their homes were identified as Hamas activists Majed Suleiman Qessiyeh, 20, and Saadi Attal, 21, said Abu Ammar, the Palestinian security official.

He said the two were from the village of Dahariya, south of Hebron, and have been missing for three days.

``We believe they are planning attacks on Israelis,'' Abu Ammar told The Associated Press. ``We are coordinating our security measures with the Israelis.''

Israeli troops arrested 11 suspected militants in Dahariya overnight. It was not immediately clear whether the arrests were connected to the reported disappearance of Qessiyeh and Attal.