Thousands of pilgrims flocked to pay homage and pray at the Hung Kings Temple in northern Phu Tho Province on the death anniversary of the nation's mythical founding fathers. 

Some families coming from far away brought sedge mats and camped outside the temple since Tuesday night, waiting for the worshipping ceremony.

Vietnamese citizens celebrate the death anniversary of the Hung Kings (2879-258 BCE) on the 10th day of the third lunar month each year. This year, the day falls on Wednesday, April 21 on the Gregorian calendar. 

A family brings chicken and sticky rice as offerings.

The festival was recognized by UNESCO in 2012 as an “Intangible Cultural Heritage of Humanity”.

At 7 a.m, the incense offering ceremony began with a procession heading to the Thuong (Upper) Temple on the Nghia Linh Mountain. The participants, dressed in traditional attire, climbed up 300 steps, taking about half an hour to reach the temple.

As a Covid-19 precaution, authorities cut out some ceremonies and numerous entertainment activities at this year's festival. 

Many members of the crowd, masked and unmasked, used their smartphones to capture the procession.

The police had set up barricades on either side of the road leading to the temple to keep the crowds at bay. On loudspeakers, they called on pilgrims to comply with Covid-19 prevention measures. 

The festival took place even as neighboring Cambodia and nearby Southeast Asian countries like Thailand and the Philippines are battling their biggest outbreaks yet, with highly infectious Covid-19 variants.

Many people sat down on the hillside, waiting for the main worship ceremony to begin.

On a corner of the hill, soldiers used binoculars to track flying objects like drone cameras. 

At 8 a.m. the crowd started flocking to the temple, prompting police and military forces to quickly divide them and prevent the situation from turning chaotic. 

Some people carried children on their shoulders as they waited. 

According to the management board of the Hung Kings Temple, more than 20,000 people attended this year's festival. 

The Hung Kings temple complex comprises the Hung King Mausoleum and the Ha (Lower), Trung (Middle), Thuong (Upper) and Gieng (Well) temples. 

The Hung King Temple Festival is one of the most important and sacred festivals of the Vietnamese people.