Hasan Abdal: Pilgrims descended from all over the world on a small town in Pakistan that is home to one of Sikhism's holiest sites this week, dipping into holy spring water and solemnly offering prayers.

They have come from India, Britain and the Middle East to the Panja Sahib Gurdwara in Hasan Abdal, 55 kilometres (35 miles) from Islamabad, where Guru Nanak, the founder of the religion, is said to have imprinted his hand.

But for Pakistani Sikhs, who mainly live in the country's restive northwest, this year's celebrations are also a time of healing after six murders during August and September that have left their community in fear. The 500-year-old religion was founded in what is now part of Pakistan, a Muslim-majority country of nearly 200 million people.

Most Sikhs left Pakistan for India after both countries gained independence from Britain in 1947. Around 20,000 Sikhs remain in Pakistan today, most in the country's restive northwest, which has been rocked by an Islamist insurgency for more than a decade, forcing many to leave their homes in the tribal areas on the Afghan border for the city of Peshawar.

There, they have set up businesses and often work as traders, their men instantly recognisable by the distinctive untrimmed beards and high turbans that distinguish them from their Muslim counterparts. They have earned a reputation for uprightness and have many loyal customers who praise their honesty.

But their peace was broken in the second half of last year with a spate of killings targeting Sikh traders and many are now considering leaving. From his spice and groceries shop in Peshawar, Harcharan Singh, 22, witnessed one of the killings last September -- that of his friend Harjeet.

"It happened in front of me. The man came, shot him and left quickly (on a motorbike) before anyone knew what was going on," he said. "Nobody knows who it was. Nobody knows who did it. Forget that -- we have had around six attacks on us. Still nobody knows who did what."

Harjeet's family fled a military operation in restive Tirah Valley in Khyber tribal agency around eight years ago, later setting up shop in Peshawar. His father, Harbhan Singh, a mountain of a man with a majestic red turban, recalled peaceful times in his beloved home where he says Sikhs were well respected and unmolested.

"We have been here long before the creation of Pakistan, before the British period. Since then, we had no worries," he said from the small living room at his home in Peshawar, flanked by Harjeet's two red-headed daughters.