CAIRO -- The Middle East is jittery as it heads into Ramadan, the Islamic holy month of fasting and spiritual introspection that has become a time of increased attacks by suicide bombers who believe they receive extra blessings.
From Iraq to Lebanon to the Sinai, the month of prayer and after-dark feasting is now a month of heightened security.
Egyptian police planned increased watchfulness throughout the month, while insisting no specific threats had been received. But Israel warned its citizens to stay away from Egypt's beach resorts in the Sinai peninsula, calling the threat of attacks substantial.
Militants have not issued specific Ramadan-related threats, but the spike in violence in recent years -- especially suicide attacks in Iraq -- has been notable.
One possible reason is the belief by some Islamic extremists that those who die in combat for a holy cause during Ramadan are especially blessed.
''This is a month that has a spiritual feel to it, which condones the issue of jihad [holy war]," said Diaa Rashwan, an Egyptian specialist on Islamic groups. Tradition holds the Prophet Mohammed led his forces in winning battles against nonbelievers during Ramadan, the ninth and holiest month on the Islamic calendar, which is based on the cycles of the moon.
Observance this year starts today across much of the Middle East, following the announcement by religious officials that the new crescent moon had been sighted Monday night.
Saturday's blasts in Bali came as Indonesia -- the world's most-populous Muslim nation -- was preparing to celebrate Ramadan, which begins there tomorrow.
In Lebanon, Ramadan comes at a time of high tension as a UN-mandated probe into former prime minister Rafik Hariri's assassination nears its end. The Lebanese fear continuation of bombings that have rattled the country since Hariri was killed.
In Egypt, an Islamic group that previously claimed responsibility for the summer attacks at Sharm el-Sheik vowed Sunday to launch an all-out war against Israelis, Americans, and Egyptian police. An Egyptian official said security was high across the country.
Israel urged its citizens not to travel to Egypt's Sinai peninsula during the upcoming Jewish holidays, which coincide with Ramadan's start, because Arab militants were planning to kidnap Israeli tourists there. ''I can say that we have very substantial information," Defense Minister Shaul Mofaz told Israel TV.
Kfir Pavzaner, an Israeli who had just returned from Sinai's Ananda Beach, described the scene: ''As soon as the warning was announced, it became like a huge storm that washed the Israelis out of Sinai."