(Adds security forces using tear gas to disperse protesters)
CAIRO, May 2 (Reuters) - Egyptian security forces fired tear gas to disperse a small group of hardline Islamist protesters who were attempting to scale the walls of the state security headquarters in a Cairo suburb late Thursday night.
Around 2,000 protesters from several Salafi Islamist groups had staged a protest earlier on Thursday night outside the security headquarters against what they said was a return to the force's pre-revolution methods.
After security forces fired tear gas, the remaining protesters, some of whom had also attempted to break into a nearby police officers' club, left the area.
The protest points to lingering suspicion harboured by the hardliners about security agencies used against them by ousted President Hosni Mubarak, and which, they say, Islamist President Mohamed Mursi has been unable to reform.
The protesters, some waving the black-and-white al Qaeda flag, chanted slogans against Mursi and accused him of building a security apparatus no different from the old one.
Earlier, at the height of the protest, no police presence was visible outside the security headquarters, where protesters tore down Interior Ministry flags and erected several al Qaeda flags and set off fireworks.
A small group had earlier on Thursday evening attempted to break down a door on the headquarter's perimeter but gave up before causing damage to the door. A Jewish Star of David was drawn by some protesters on the wall's perimeter.
The Salafi groups had issued a statement earlier in the day saying state security organs had returned to "criminal practices" such as summoning citizens for investigation, threatening the achievements of the 2011 uprising.
Egypt dissolved the feared and hated state security apparatus, which had been used by Mubarak's administration to crush political opposition, including Islamists who were repressed under the old guard, the month after he was toppled.
It was replaced by a new National Security Force, which the Interior Ministry promised would serve the nation without interfering in the lives of citizens or their right to exercise their political views.
The protesters had marched from a nearby mosque after evening prayers. Some chanted to onlookers in apartments on streets clogged by the march "come down from your houses, state security is Mubarak".
The system of law and justice has been a major stumbling block in post-Mubarak Egypt. A rift between the Islamist rulers and the judiciary, which Islamists see as controlled by Mubarak loyalists, is steadily widening amid a broader struggle over the future character of the country.
Earlier on Thursday, an Egyptian judge referred a complaint filed by a police spokesman against popular hardline Islamist cleric Hazem Salah Abu Ismail to the state security prosecution, setting a hearing for Saturday to begin the investigation.
State newspaper Al-Ahram reported that the complaint called for Interior Minister Mohamed Ibrahim to arrest Abu Ismail on charges of "terrorising police officers" after Abu Ismail urged his supporters to attend Thursday's protest.
The police spokesman's complaint added that such demonstrations hindered officers in their work to protect national security. (Reporting by Abdelrahman Youssef and Ali Abdelaty; Writing by Maggie Fick and Tom Perry; Editing by Alison Williams and David Brunnstrom)