
The PAD guards filed complaints with police that the attack at the Makkhawan bridge came at about 3 am.
Pol Captain Pomphet Chotklang of Nangloeng police station said the bomb was a grenade. A safety pin was found at the scene.
The bomb caused a small hole on the ground.
Six guards were rushed to the Vajira Hospital. One of them was fatally injured. He is identified as Sathien Thapmaliphol, 43. He subcumed to head injuries and died at the hospital in the evening.
Four other guards received minor injuries and received treatment by the PAD medics.
PAD guards told police that the captured a man at 2 am after he carried a shirt soaked with petrol walking to the rally site at the Makkhawan Bridget.
Shortly after the man was captured, a motorcycle arrived and the pillion rider threw the bomb at the PAD guards.
Following the attack, the PAD stepped up security at the site.
About an hour after the bomb attack, a few gun shots were heard near the Government House.
At about midnight, a bomb was lobbed into the compound of the house of Constitution Court judge Jaral Phakdeethanakul, causing some damages.
No one was injured in the attack happened at Jaral's house on Soi Pridi Phanomyong in Bangkok's Klong Tan district.
Bomb disposal officers said the bomb was made of TNT explosives stuffed inside a PVC pipe.
Police Sub-Lt Somchai Saraket of Klong Tan police station quoted Jaral as saying he heard something falling on the roof and heard an explosion two minutes later.
The explosion caused a 50-cm-wide and 25-cm-deep hole in the lawn and shattered some window glasses as well as damaging an air-condition compressor.
At about 5:30 am, police said a man clad in black was found dead on the a sidewalk about 50 metres away from the Misakawan Intersection behind the Metropolitan Police head office.
A policeman, who was stationed to keep security near the area, said he saw the man walking through the police line at 4 am heading to the Government House.
The man, Sungwian Rujimora, 46, appeared drunk and was heard saying "fight them".
He was found hundreds of metres away from the Government House.
Police said he was shot and beaten with hard objects.