Regular weapons searches may be conducted at Victoria prison after two guards were attacked with sharpened toothbrushes by Vietnamese migrants awaiting repatriation. The two incidents, one left a guard requiring stitches, were expected to accelerate the construction of special security units in detention centres. Both migrants - north Vietnamese and labelled as 'troublemakers' - have been put in isolation units while police investigate. At 11.45 am on Tuesday, a migrant returning from a washing area lunged at a 38-year-old guard, stabbing him in the face, a Correctional Services Department spokesman said. At 8.30 am yesterday, a migrant returning from slopping out used a similar instrument to slash a 32-year-old guard's face. Correctional Services officials have until now ordered weapons searches only at detention centres, less secure locations where violence was more likely. Asked whether similar searches would now take place at Victoria prison, a prison source said: 'I think we are going to have to do that. We have no choice really.' Staff from other facilities were being brought into Victoria to boost the 162-strong staff contingent to 208. The Correctional Services spokesman said both incidents appeared to be a ploy to delay repatriation to Vietnam. During questioning, the first assailant said the officer would not allow him to leave his cell for more than the stipulated period. The second suspect said the officer had shouted at him. While most Vietnamese migrants are held at detention centres, troublemakers are often transferred to crammed prisons for security reasons. Other Vietnamese are sent there before boarding repatriation flights. It emerged last week that plans were under way to build security units at Whitehead and High Island detention centres to house troublemakers in a bid to reduce the scope for violence in the wake of the May Whitehead riots.