Thailand's Prime Minister Abhisit Vejjajiva has promised to reveal new information about last year's political violence during an election rally Thursday at the scene of the deadly Red Shirt protests.

Authorities deployed hundreds of police to the scene for fear of violence, while Red Shirt leaders ordered their followers to stay away from the central Bangkok location. Opposition members say Mr. Abhisit's choice of location is an insult to the families of more than 90 people who died when police broke up the six-week-long protest in May 2010.

Polls for Thailand's July 3 election show Mr. Abhisit's Democrat party is trailing the Puea Thai party led by Yingluck Shinawatra. She is the younger sister of exiled former prime minister Thaksin Shinawatra, whose ouster in a 2006 coup helped lead to the Red Shirt protests.

Mr. Abhisit told reporters Wednesday he thinks voters have been influenced by criticism of his government's handling of the protests, and that the rally was intended as an opportunity to clear up misunderstandings.

More than 100,000 people took part in the Red Shirt protests, tying up several blocks of the city's central financial district for weeks in April and May, 2010. Both sides continue to argue over who was responsible for the violence, in which several police were killed along with dozens of protesters.