At least 21 people, including a Singaporean woman, were killed and more than 120 wounded in a bomb blast at the popular Erawan Shrine in Thai capital Bangkok.

The unprecedented attack aimed at killing as many people as possible as the shrine is crowded at around 6 to 7pm, police spokesman Prawut Thavornsiri told AFP on Tuesday (Aug 18). Thai authorities said the blast was targeted at foreigners.

Other than the Singaporean, citizens from China, Hong Kong, Malaysia and the Philippines were reported to be among the dead. The blast occurred at a major traffic intersection beside the shrine, which is flanked by upscale hotels and shopping malls. Here are 5 things about the location of the blast.

1. Why was the shrine built?

It was erected in 1956 to ward off evil that was believed to be stopping the construction of a luxury hotel named Erawan Hotel. The first stages of building were beset with problems such as injured construction workers and the sinking of a ship carrying marble for construction.

Superstitious labourers refused to continue work, and a Hindu priest was consulted. He pointed out that the foundation stone that was laid was inauspicious. He advised that a shrine should be built to improve the situation. Since the hotel was to be named after the elephant escort of Indra in Hindu mythology, the priest determined that Erawan required a passenger, and suggested it be that of the Hindu god of creation, mercy and benevolence, Lord Brahma. A four-faced statue of Lord Brahma was built, and the misfortunes miraculously ended. While the original hotel was demolished in 1987, the shrine remained. The property was replaced by the privately-owned Grand Hyatt Erawan Bangkok on the same site in 1991.

2. Where is the shrine?

The Erawan shrine is near the the busy Ratchprasong Junction - the centre of the wealthy Ratchprasong shopping district, which is the site of many a traffic jam. It is also a site of political importance following a series of anti-government protests there in 2010.

Members of the National United Front of Democracy Against Dictatorship (UDD), also known as the Red Shirts, occupied the area around the junction during the protests, calling for democratic elections after Prime Minister Thaksin Shinawatra was deposed in a military coup in 2006. The camp there was eventually cleared by the military, beginning a violent crackdown against the movement which resulted in the deaths of around 90 people.

3. What happens at the shrine?

Thousands of people throng the shrine daily. They usually visit the shrine to pray for the fulfillment of a wish. Visitors range from infertile couples seeking children to entrepreneurs to people seeking an edge in the lottery. They pray by offering items such as flowers, fruits and teakwood elephants. They also light incense and candles.

They also vow to return to offer their thanks should their wishes be fulfilled. While several items can be offered in gratitude, a popular way for devotees to offer thanks is to pay dancers at the shrine to perform for the statue. According to Lonely Planet, the money paid goes to to a charity run by the Grand Hyatt Erawan. In a rare case in 1991, a visitor disrespectfully left a pornographic videotape as an offering.

4. Who visits the shrine?

Among Singaporean celebrities who have who prayed at the shrine are actress Fann Wong, hairstylist David Gan, and actor Li Nanxing. Wong was suspended by the then Television Corporation of Singapore (TCS) in December 1996 in a dispute over her prior contract with a Taiwanese production house. In March 1997, on the advice of friends, she headed for Erawan Shrine to make offerings to reverse her luck, reported Lianhe Wanbao. Her buddies - former actor Xie Shaoguang, actor Chen Hanwei and Gan accompanied her. By the end of that year, she was filming again and even won a Star Award for popularity. She went on to star in a major Hollywood movie, 2003's Shanghai Knights, opposite Jackie Chan.

Gan has been a regular visitor at Erawan Shrine for more than 20 years, since he set up Passion salon. According to a Straits Times report in 2006, he visited the shrine once a month or even once a week when he was troubled.

Li, the former king of Caldecott Hill, prayed at the shrine in 1996, when he was having a spate of bad luck.

Others who have prayed there include Hong Kong film star Deborah Li, her son, singer Nicholas Tse, and Hong Kong actors Aaron Kwok, Sammo Hung and Tony Leung Chiu Wai, and Taiwanese actress and model Shu Qi.

5. What other incidents have happened at the shrine?

A 26-year-old mentally disturbed man was beaten to death in 2006 by street sweepers who saw him attacking the Erawan Shrine with a hammer. The man had broken into the shrine. The two street sweepers were arrested and charged with second-degree murder.

At the time, some saw the incident as a bad omen for the country's political crisis, with daily demonstrations aiming to oust then-Prime Minister Thaksin Shinawatra on charges of corruption and abuse of power.

Thai media reported at the time that an astrologer said that the attack might actually ease the turmoil. In its destruction, the shrine had made a self-sacrifice and borne the bad luck plaguing Thailand, Thai media quoted the-then police general and acting deputy prime minister Chidchai Wannasathid, as saying. Thaksin, who is currently in exile, also visited the shrine in 2006 and set free nine birds as part of a ritual.