Prices have, in fact, almost doubled since last month, astonishing food suppliers, according to Viet Nam's ThanhNien News.com.

Phung Khoi Phuc, director of the Dong Nai food processing plant in the province of the same name, acknowledged demand for chicken has been soaring recently.

“A kilogram of live chicken has risen to VND42,000 from VND25,000 last month,” he said.

“Free-range and caged chickens have also seen their prices go up by around VND4,000 a kilogram [since last month],” Phuc said.

He blamed it on three factors. Chicken farmers might have hoarded stocks thinking demand for the meat would soar ahead of the holidays, he said. He was referring to a four-day holiday starting on April 30, Liberation Day.

They might have downsized operations after the Tet (Lunar New Year) holiday in January, while import of chicken meat has seen a slowdown since foreign plants have trimmed their output, he added.

“Egg prices have [also] increased by up to 20 per cent since last month,” Truong Chi Thien, director of Vinh Thanh Dat Food Company, said.

But poultry is just one of the many items that have become more expensive ahead of the long weekend.