WHILE the prime minister and relevant agencies appear to have no idea who planted the bomb at Phramongkutklao Hospital on Monday, First Army Area chief Lt-General Apirat Kongsompong said a unit under his command was ready to hunt the culprits down.

“We are ready but our superiors always insist that we should not take any action against any group without clear evidence,” Apirat said yesterday, adding that the suspects “in his mind” were probably both inside and outside the Kingdom.

Police struggled yesterday to pinpoint suspects, with authorities saying they did not have a clue so far to indicate any particular group.

Meanwhile, Prime Minister General Prayut Chan-o-cha said yesterday the hospital bomb, which injured 25 people, was unlikely to be linked to the junta’s third anniversary on the same day.

“We’ll have to wait for investigation results,” Prayut said after the Cabinet meeting. “[But] I don’t think this will be related to our anniversary and we won’t make a big deal about that assumption. Otherwise, we’ll be affected a lot.”

He also played down the fact that the bombing occurred in a room named after his right-hand man, Deputy PM and Defence Minister General Prawit Wongsuwan.

“I don’t take it as a challenge or anything. Everything will have to be dealt with by the law,” he said.

The First Army Region, which oversees security in the capital, has stepped up measures to ensure public safety after three small bombs were detonated in Bangkok since early last month.

Another 200 closed-circuit cameras were installed across the capital and extra officials were patrolling in collaboration with the Bangkok Metropolitan Administration, Apirat said.

Security checkpoints will be set up at 27 locations in the capital to operate 24 hours a day in response to the blast, deputy national police chief Pol General Chalermkiat Srivorakan said.

Meanwhile, Athikom Intuputi, secretary-general of the Office of Judiciary, said safety measures at Ratchadapisek Court compound had been strengthened following the hospital attack. Cars entering and exiting the compound would be checked, he said.

Authorities also said surveillance cameras were a problem at Phramongkutklao Hospital, as they were often out of order. Of 13 cameras inside the hospital, nine are broken. And police said it was unclear how many of the 64 CCTV cameras in the medical compound work properly.

The prime minister said he had ordered a serious investigation into the state of CCTV cameras at the scene, but revealed little about the junta’s thoughts on the incident. “If you want to know what the objectives of the bombing were, you’ll have to ask the perpetrators,” he said.

In response to speculation that the junta may have been behind the blast, Prayut said junta leaders would never commit such an act. The incident was “unforgivable” and “severely breached human rights”, the premier said.

“How could any government be that crazy to do this kind of thing? Except for some [people] who want to be in the government and could think of doing it.”

He added that a bomb at the hospital was unexpected. “Security forces have kept up with evaluating the situation and intelligence. Still, who would anticipate that this would occur at the hospital? Well, those bad people do,” he said.

The pipe bomb was a homemade device detonated by an integrated-circuit timer. Planted in a vase, it was relatively small, with only one pound of explosive. The bomber must have known the location well – he or she might have mingled with patients to place the bomb at around 8am on Monday when the hospital opened for regular service, an official on the investigation team said.

Police said they were reviewing pictures in news reports that showed three men sitting near the vase in which the bomb was hidden.

Police believed the men were |closest to the bomb and may be among the injured, deputy national |police chief Pol General Srivara Rangsibhramanakul said.

Meanwhile, on the third anniversary of the junta taking power on Monday, Prayut refused to spell out exactly when an election would be held, only saying authorities would follow the “roadmap to democracy”.

“The country must be at a peaceful stage … whether an election will happen depends on you people,” he said.