Israel on Friday closed off the Palestinian territories for 48 hours, ahead of the solemn Jewish holiday of Yom Kippur which begins at sunset.
A military spokesman told AFP that crossings were closed from midnight Thursday and would reopen at midnight on Saturday.
Israel seals its borders with the Palestinian territories during its main holidays, citing the increased risk of militant attack as large numbers of Jews congregate for worship.
The actual holiday for the Day of Atonement, which observant Jews will mark with prayers and fasting, begins in Jerusalem at 1512 GMT and lasts until 1623 GMT Saturday.
During that time all work, traffic, and TV and radio broadcasts will cease.
Public transport will stop running by 1200 GMT and Israel's airspace will be closed from 1100, public radio said.
Seaports and land borders with Jordan and Egypt will also shut down.
Signup to our newsletter and follow us on Facebook and Twitter!
Police said they were deployed in strength throughout the country, particularly at synagogues, which attract large crowds over the holy day.
Police spokeswoman Luba Samri said officers in mixed Arab-Jewish cities would seek to prevent friction between Christians celebrating the feast of the Holy Cross on Saturday and their fasting Jewish neighbours.
National police chief Yohanan Danino has called on both communities "to respect one another and show restraint," she said.
In the northern port city of Haifa, senior police officers met with Israeli Chief Rabbi David Lau and Greek-Catholic Melkite Archbishop Elias Shakur to coordinate efforts aimed at preventing trouble, including re-routing or postponing Christian parades, news website Ynet reported.
Samri said that restrictions would be imposed on Muslims attending Friday prayers at Jerusalem's Al-Aqsa compound, for reasons unconnected with Yom Kippur following repeated clashes there with stone-throwing Palestinians over the past week.
She said that entry to men would be limited to those aged 45 and over who hold a Jerusalem residence permit, but women would be subject to no restrictions.
"There's intelligence information of the intention by Arabs to disturb the peace at today's prayers on Temple Mount," she told AFP using the name by which Israel refers to the compound housing the Al-Aqsa and Dome of the Rock mosques.
It is the third holiest site in Islam after Mecca and Medina in Saudi Arabia.
Jews venerate the same location as the site of biblical Jewish temples and it is a regular flashpoint for clashes.