For many residents in the Southern Chinese town of Yulin, the height of summer marks the perfect time to get together with family and friends, eat lychees and feast on copious amounts of dog meat.

Thousands of dogs are expected to end up on the chopping block during the city's annual dog meat festival, which marks the peak of summer. This year it falls on Monday 22 June, although the build-up begins days earlier, with locals getting together to eat dog meat and lychees, two foods considered to have "hot" energy.

"It's healthy, just like raising pigs or chickens, it's fine. But you definitely must not eat dogs if you don't know the source, or dogs which have illnesses", said 35-year-old local Teng Jianyi, as he tucked into dog meat with some friends.

But in recent years the event has found itself in the firing line of China's nascent animal rights movement, turning Yulin into a battleground between those who want to protect man's best friend and those who would rather just eat its meat.

The city's dog market has become a place where those pro and anti the dog meat trade clash. In the sweltering heat, tempers can often flare.

"There are all sorts of cultural norms about what you can eat, you eat turkey, so why are you trying to force us not to eat dog meat?" shouted one dog meat supporter.

Some campaigners like Yang Xiaoyun take a direct approach to saving Yulin's dogs, choosing to buy them up to take them off the market.

Last year Yang made newspaper headlines after spending 150,000 yuan (£15,264, $24,160, €21,296) on rescuing about 350 dogs.

This year Yang, who comes from northern China, hopes to set up a home for the rescued dogs near Yulin. Her current base lies hidden away at the top of a hill in the surrounding countryside, though locals have already made it clear she is not welcome, threatening her to leave.

Yang said she recognised her actions were a drop in the ocean compared with the number of dogs that would be slaughtered.

Paradoxically, people like Yang may be encouraging more traders to bring dogs to Yulin in the hopes they will be snapped up by well-meaning activists. Yang said she has received phone calls from people promising they would bring even more dogs for her this year.