First there was one, then another, and in a matter of seconds there were four dogs bounding after his bicycle, barking madly.
Frightened and outnumbered, Mr Jim Tietjen, a 61-year-old consultant who was cycling around Bukit Brown cemetery yesterday morning, pedalled even faster, telling himself "life is speed" as the dogs chased him down a narrow forested road lined by graves.
Just as he rode past what looked like a shack in the woods, a fifth canine "came out of nowhere" and leapt straight at him, causing him to swerve and fall off his bicycle.
Too shocked to move, Mr Tietjen began screaming in pain and for help, and it was only then that the pack of dogs backed off.
Mr Tietjen, who has lived in Singapore for the last 13 years, said he called an ambulance and went to lodge a police report. "They were vicious, and my personal concern is public safety, because that's a public road," he said, adding that the police referred him to the Agri-Food and Veterinary Authority of Singapore (AVA), which said it is investigating the case.
The American citizen cycles often in the Bukit Brown area but said yesterday's canine encounter was the first. He was not bitten but suffered scrapes and soft tissue injuries, and was treated at Mount Alvernia hospital.
When The Sunday Times visited the location of the incident, there were six dogs being fed by groundskeeper Teo Hock Chuan, 64, who has lived in a large sheltered grave, the "shack" Mr Tietjen had seen, for more than 20 years while caring for some 100 graves.
When approached, Mr Teo said he feeds a pack of eight strays that have been wandering around the hilly cemetery "for many years", and has never once seen them attack people.
"They don't bother anyone, but they do chase after things that move fast like motorcycles and bicycles, so maybe that's why they went after (Mr Tietjen's) bike," he said, adding that he does not look after the dogs beyond leaving them food each day.
An AVA spokesman said, however, that dogs must be properly homed and cared for, and the public "should not feed stray dogs as this encourages breeding".
Stray dogs can develop a pack mentality and be a risk to public safety, said the AVA. In an encounter, people should stay calm, avoid going near the dogs and walk away in the opposite direction.
In December 2011, two joggers were attacked by a pack in Punggol. That year, the AVA caught some 1,500 strays. Animal welfare groups estimate that there are 8,000 strays in Singapore and work with AVA to rehome caught animals.
A shaken Mr Tietjen said he would like to see the authorities round up the dogs. "You can't just let wild dogs run around terrorising people, so the AVA should try and catch them," he said.