Several demonstrators and two news-crew members were reportedly hurt by rubber bullets during attempted raids by protesters into restricted areas.
The Centre for Administration of Peace and Order (CAPO), however, has insisted that police are still relying only on tear gas and chemically treated water spray to keep the demonstrators away.
Navamindradhiraj University president Bhichit Rattakul confirmed that at least two patients, one of them a reporter, were shot with rubber bullets and sent to the Vajira Hospital. The hospital is part of his university.
He said the hospital planned to examine the water mixture found on patients from rally sites too, because most patients had developed skin rashes.
"We will be examining the water mixture to determine what it contains," he said.
Surachet Watcharawisit, chief photographer of the Daily News newspaper, reportedly sought treatment at the Hua Chiew Hospital yesterday after being shot in the ear by a rubber bullet. He needed 23 stitches.
As anti-government protesters clashed with police yesterday at several sites around Bangkok - including Karn Reun Intersection, Pol 1 Intersection and Chamai Maruchet Bridge - word spread that live bullets were being fired along with rubber bullets and tear gas. During the chaos, it was also reported that a news van from Media News was shot at, while an Al Jazeera news van reportedly sustained two shots from an unknown type of bullet.
At 3pm, Students and People's Network for Thailand's Reform (SRT) leader Kittichai Saisa-ard called on its supporters to retreat, explaining that police were using heavy weapons in response to the use of ping-pong bombs by unidentified men.
Police, however, insisted they used neither real nor rubber bullets.
"We don't use [such] force," CAPO spokesman Maj-General Piya Uthayo told a press conference yesterday afternoon.
CAPO secretary-general General Worapong Chewprecha, who is also a deputy national police commissioner, explained there were clear standard measures to stop any attempt to prevent the situation from getting out of control.
"Our measures correspond to actions taken by demonstrators," Worapong said, "Any use of force will ease as soon as demonstrators go for lighter measures."
He said if demonstrators gathered peacefully, police would just give information and advice.
If demonstrators committed minor offences, police might try to negotiate and use pressure tactics, he said.
"We may need to use some tools too, but those tools will not endanger demonstrators' lives," he said.
Worapong said police would issue warnings before any use of tear gas, water cannons, and rubber bullets.
"In those cases, after the situation eases, we will also deliver medical help to injured demonstrators," he said.
He insisted that tear gas used by police was not dangerous.
"I have tested it myself. After exposure, I had an eye irritation but only for a while," he said.
Worapong said police did not use tear-gas launchers, out of concern they might be mistaken for grenade launchers.
Still, he said if the situation descended into a riot, police would need to use the harshest measure - the use of live bullets