Muslims entered the fasting and feasting month of Ramadan on Saturday with swine flu and the economic downturn adding to security fears in several Islamic countries in dampening the mood.
The threat from the A(H1N1) virus prompted a string of governments to place restrictions on citizens making the pilgrimage to the holy places in Saudi Arabia traditionally made by many Muslims during Ramadan, while financial worries forced many families to cut back on their holiday spending.
In the Saudi cities of Mecca and Medina, which normally do a brisk trade from pilgrims during Ramadan, businesses were braced for their worst holy month in years.
In neighbouring Medina, officials said they expected business to be down by 70 percent.
Saudi newspapers showed pictures of pilgrims wearing face masks to ward of the swine flu, which has killed 16 people and infected more than 2,000 in the kingdom.
Shiite Iran banned its citizens from making the pilgrimage and cancelled all flights to the kingdom for the duration of Ramadan.
A string of religious authorities across the Arab world also urged the faithful to stay at home this year.
In the Saudi capital shoppers jammed supermarkets until late into the night on Friday to stock up their larders for the extensive iftar meals served to family and friends after the daytime fast ends.
Satellite TV networks launched special programming of serial dramas, sitcoms, talk shows and films in a bid to grab market share in the peak viewing period of the year.
Arab News columnist Tariq al-Maeena bemoaned the commercialism that has overshadowed Ramadan's spiritual roots.
"It is a month of introspection, a month of mercy, patience and self-discipline," he wrote.
"Instead, what has been evident are the heavily advertised television serials ... bound to take the viewers away from their activities of faith and keep them up all night."
In other parts of the Arab world without the kingdom's massive oil wealth, financial fears meant families approached the holy month far more cautiously.
In Algeria, where past Ramadans have been marred by flurries of attacks by Islamist militants, families said they were now more worried about their pockets. Some 1.2 million disadvantaged families will get state help this year to cope with the costs of the holiday.
"Security is far from being our main concern," said Abdelalik, sitting with his wife at a seafront cafe in the resort town of Boumerdes, east of the capital Algiers, which is still regarded by the army as a high-risk zone.
"I'm mostly concerned about making it to the end of the month," he said.
In other parts of the world though, security remained a pressing issue. In Muslim-majority southern Thailand -- scene of a five-year-old insurgency that has killed 3,700 people, rebels killed three security volunteers and three civilians on the opening day of the fast.
Iraq too remained on tenterhooks after two deadly bombings in the heart of Baghdad on Wednesday ratcheted up tensions between the Shiite majority which leads the government and the disenchanted Sunni Arab former elite.
In a break with the communal rivalries of previous years since the US-led invasion of 2003, Sunnis and Shiites marked the start of the Ramadan fast on the same day this year.
But dozens demonstrated against government plans to remove concrete blast walls from Baghdad's oldest thoroughfare, Al-Rasheed Atreet.
"If they open up the road, we will be the first victims of explosions during Ramadan," said Adel Abu Mohammed, a 30-year-old street vendor.
In a new bid to improve US relations with the Islamic world marred by the war in Iraq, President Barack Obama sent a Ramadan message to Muslims promising "concrete actions" and a "new beginning."
"I know this to be a festive time," he added, alluding to his father's Muslim background.
In the United Arab Emirates capital of Abu Dhabi, police announced they would be giving out 35,000 free iftar meals to commuters in a bid to curb road accidents caused by drivers speeding to get home in time for the breaking of the fast, the Al-Khaleej newspaper reported.