A truck full of rockets exploded at a military facility near the home of Prime Minister Hun Sen Sunday, injuring at least two of the premier’s bodyguards, officials said.

The office of the prime minister issued a statement saying a driver of the truck and an assistant had been hurt in a series of blasts near the residence, in Kandal district outside Phnom Penh, and an investigation into its cause was underway.

Gen. Hing Bunheang, chief of Hun Sen’s bodyguard unit, told VOA Khmer Monday mechanic had accidentally lit a fire, which ignited the rockets and damaged a total of five vehicles.

Om Yentieng, a senior adviser to Hun Sen, confirmed the explosion had occurred and said the cause of the blast came from within the compound.

The explosion, which occurred around 7:30 pm, frightened nearby residents.

One woman who asked not to be named said she heard the blast and thought at first it had come from a truck tire, but then subsequent explosions continued for 20 minutes. Her father warned her they were rocket explosions.

“Some people brought their motorcycles and cars inside their homes and closed the doors, because they were afraid of the rockets,” said the woman, who lives 3 kilometers from the facility.

At that distance, military police and police blocked National Road 21, allowing only emergency vehicles to pass. An ambulance, fire trucks and a demining truck from the Cambodian Mine Action Committee were seen driving toward the site.