M67 grenade, part of army and police weapon cache, used in attack on Tuesday.
Explosive Ordnance Disposal chief Pol Colonel Kamthorn Uicharoen said yesterday that a grenade lobbed at the police during the operation to reclaim the Phan Fah Lilat Bridge area from protesters on Tuesday was a highly destructive M67 grenade, not a stun bomb as some people had speculated.
A video clip showing a police officer kicking the grenade away from himself and his colleagues before it exploded went viral on social media recently. The police officer and other security officials nearby were badly injured by the explosion.
Lt-Colonel Songpol Iambunrit, a member of the Defence Industry Club, said US-produced M67 grenades are used by soldiers and the police, adding that he suspected that the assailant who hurled the grenade on Tuesday was highly trained because the safety clip could not be found at the scene.
He also dismissed claims that the grenade used on Tuesday was a stun bomb, saying stun bombs release white smoke after exploding, but the smoke exuded by the grenade in question was black.
Meanwhile, Lt-General Paradorn Pattanatabut, who is secretary-general of the National Security Council, said investigators would study the trajectory of the bullets shot at protesters, though he admitted that forensic scientists had problems accessing the scene.
However, he said, it was clear that some people wanted to instigate violence judging from the direction the bullets and bombs were fired from, and the fact that the attacks are believed to have been carried out by highly skilled people. He also cited the instance of PDRC leader Somkiat Pongpaiboon being released from police custody by highly trained men.
Paradorn said that the police had used the correct measures in conducting the "Peace for Bangkok" operation - having officers on the frontline only carry shields and batons, with armed officers holding up the rear to protect the unarmed frontline officers in case of emergency.
"The protesters were naturally enraged from the onset. Armed police would not aim to kill, but would protect their colleagues from being attacked while making a retreat. On Tuesday, they could hardly do their duty because there were too few of them compared to the large number of protesters," he said.
He said that after Tuesday's clash in the Phan Fah Lilat Bridge area, security officials would not leave anything to chance.
"There is a possibility that violence will continue, because the protesters are still angry," he said.
Meanwhile, he implied that it was possible that caretaker Prime Minister Yingluck Shinawatra might shift her temporary office now that the People's Democratic Reform Committee has besieged the Office of the Permanent Secretary for Defence, where her temporary office was initially based.