Christmas church services and other celebrations are being held this weekend under the gaze of armed guards and security cameras in many countries after Islamic State gunmen attacked a Methodist church in Pakistan as a Sunday service began.
Majority-Muslim countries in Asia and the Middle East were particularly nervous after US President Donald Trump's recent announcement he intends to relocate the US embassy in Israel to Jerusalem, a decision that has outraged many Muslims.
In Indonesia, the world's biggest Muslim-majority country, police said they had stepped up security around churches and tourist sites, mindful of near-simultaneous attacks on churches there at Christmas in 2000 that killed about 20 people.
Muslim volunteers in Indonesia are also on standby to provide additional security if requested.
In Cairo, where a bombing at the Egyptian capital's largest Coptic cathedral killed at least 25 people last December, the interior ministry said police would conduct regular searches of streets around churches ahead of the Coptic celebration of Christmas on January 7.
Egypt's Christian minority has been targeted in several attacks in recent years, including the bombing of two churches in the north of the country on Palm Sunday in April.
German police brought in experts and an explosives robot to investigate a suspicious package at a Christmas market in the city of Bonn late on Friday.
Germany is on high alert a year after a failed Tunisian asylum seeker killed 12 people when he hijacked a truck and drove it into a Berlin Christmas market.
In the Pakistani city of Quetta, members of a Bethel Memorial Methodist church were repairing the damage done by a pair of suicide bombers who attacked during a service last Sunday, killing 10 people and wounding more than 50.
Broken pews and damaged musical instruments were still strewn around church grounds on Thursday, with about a dozen police standing guard.
The government of Baluchistan province, of which Quetta is capital, plans to deploy 3,000 security personnel in and around 39 Christian churches this Sunday and Monday.
Provincial police chief Moazzam Jah Ansari told Reuters volunteers from churches were also being trained to conduct body searches and identify worshippers entering churches.
Pakistan's Christian minority, which makes up about 1% of the population of 208 million, has been a frequent target, along with Shia and Sufi Muslims, of Sunni Muslim militants.
Jerusalem, revered by Jews, Christians and Muslims alike, is home to Islam's third holiest site and has been at the heart of the Israeli-Palestinian conflict for decades. Israel captured Arab East Jerusalem in 1967 and later annexed it in an action not recognised internationally.
Protests across the Muslim world in Asia and the Middle East have largely been peaceful.
In Jerusalem itself, an Israeli police spokesman said there were no new security measures but police would deploy forces as usual around Christian holy sites including the Church of the Holy Sepulchre and also secure convoys of worshippers from the West Bank city of Bethlehem, traditionally known as the birthplace of Jesus Christ and run by the Palestinian Authority.
Many Palestinian Christians oppose Trump's announcement and say they have no fear of attacks.
"Trump's decision offended all Palestinians, be they Christians or Muslims. Why would we feel threatened by Muslims?" said George Antone, a Catholic who lives in Gaza, which is run by the Palestinian Hamas group.