BANDA ACEH, Indonesia (Reuters Life!) - It looks like a typical day at the beach: children frolick in the waves, girls chat by the beach front and music blares from a radio perched by a group of young men.
But this is Banda Aceh, the only province in majority Muslim Indonesia that uses Islamic sharia law as its legal code, and the mood at the beach becomes instantly tense as a group of policemen who strictly enforce this law pull up in pick-up trucks.
The police unit, called the "Wilayatul Hisbah", is looking for unmarried couples, Muslim women without headscarves or those wearing tight clothes, and people drinking alcohol or gambling.
Amid the throngs of people at the beach, there are always couples. The young men and women sit modestly apart, but they are still targets of the sharia police.
"You are not married, you should not be here together. You must leave now," says one officer to a couple, who sullenly walk to the parking lot as crowds silently watch.
Girls wearing tight trousers are also reprimanded.
"You should be ashamed of yourselves for dressing this way," says the officer to two youngsters in jeans. "Go home and change into something more modest."
Indonesia is the world's most populous Muslim nation, but nowhere is the faith more strictly interpreted than in Aceh, sometimes referred to as the "verandah of Mecca" because it was one of the first parts of the archipelago to turn to Islam.
Aceh won the right to use sharia law -- Indonesia is officially secular -- as part of a 2002 autonomy deal intended to end a decades-long conflict between Muslim separatists and the military in which thousands died.
A further 160,000 died in the 2004 Indian Ocean tsunami, which paved the way for a peace agreement between the two sides and brought in billions of dollars of foreign aid.
Since then, the devout province has tried to counter the Western influences brought in by foreign aid workers.
It has also ramped up its efforts to enforce a strict version of Islam recently, including proposing a law that calls for adulterers to be stoned to death as well as plans to introduce a regulation forcing women to wear modest clothes that do not reveal the shape of their body.
The sharia police unit was created in 2002, and to date, say they have punished 126 people, mainly gamblers and drunks with caning the most extreme punishment.
"We do this sort of prevention without taking aggressive action against possible offenders so that people will understand the purpose of our patrol," said Marzuki, head of Aceh Provincial Sharia Law Department.
However, the rising fundamental tide in Aceh has human rights groups and local businessmen worry this attitude will scare away foreign investment needed to rebuild the economy five years after the Indian Ocean tsunami.
Not everyone in Aceh is also happy with the intrusion into their private lives.
"I think it's a violation of human rights, but the rules being applied in Aceh such as you should not dress in tight clothes that show off the shape of your body, are still reasonable," said college student Ramadhan Alfian.
Many Acehnese worry the sharia police may increase their clout on the back of the rising tide of fundamentalism, but not many object publicly for fear of being branded bad Muslims.
"The sharia police are only doing their duty, it is the responsibility for each individual to implement Islamic values," said resident Said Hamzah Al-Hasni.
Editing by Miral Fahmy