Sir Hugh Orde has defended the PSNI's response to racist violence after the home of another Romanian family was attacked on Wednesday night.
A window was smashed at the property on the Upper Newtownards Road, Ballyhackamore.
The property is a three-storey house on the edge of a busy road in east Belfast.
The bathroom window was smashed during the attack, which community representatives said left the inhabitants terrified.
The family has said they are considering fleeing.
Sorin Ciurar, 20, said: "I am frightened. I don't know what we are going to do now."
The group, three generations of Romanians, had moved in around four months ago and local representative Andy Moorhead insisted there had been no attacks on them before.
He said: "This is one of the most culturally diverse areas but we have a raft of problems with vandalism and anti-social behaviour,"
"This is a close-knit community but we can't find out at this stage who is responsible for this.
"If it is a racist attack, it is certainly an isolated incident. There are many minority groups here and there has not been any significant problem."
The group were sheltering inside the building on Thursday morning and children were seen peering out of the bedroom windows.
'Complicated picture'
Officers are treating the incident as a hate crime, a police spokesman confirmed.
But Sir Hugh Orde denied claims that his officers were slow to react to the original spate of attacks in south Belfast that forced over 100 Romanian people from their homes.
He said police responded promptly to calls for help and insisted that officers took racist crime very seriously.
He said: "It is a complicated picture. We had seven calls for assistance over a period of four-and-a-half to five days.
"I have to say some of those calls were not, on arrival, discovered by the officers to be crimes between different communities.
"They were indeed, on one occasion, a dispute between different families from the Romanian community."
It came as other Romanian families spent the night in safe accommodation after a spate of racist attacks.
The police response to the attacks was supported on Thursday by Northern Ireland's Policing Board.
Chairman of the board, Barry Gilligan, said members were unanimously satisfied with the police response and that there had been inaccuracies in suggestions that police had not responded quickly to pleas for help.
He said: "There is a factual record which shows the response ran from immediate to 10 minutes. There is no question of 999 calls not being responded to after 90 minutes."
But Mr Gilligan added: "We do say this is not a matter for the police alone.
"This is a wider societal issue. There is a huge problem in our society with racism and sectarianism and we as a society have got to deal with it, not just the police."
Talks
Meanwhile, Romania's consul general held high-level talks at Stormont on Thursday.
Dr Mihai Delcea intervened when over 100 of his countrymen fled their south Belfast homes to shelter in a church hall and later, a leisure centre.
Police have said they do not believe paramilitaries were involved in orchestrating the attacks.
Police Supt Chris Noble said: "The information we have at this point in time is that it was a sporadic attack.
"It was a sporadic attack by a number of youths with no affiliation or co-ordination.
"What I can guarantee is a commitment from the police service in terms of visible, responsible policing."
Safe temporary accommodation has been provided for the families in Belfast for one week.
Michael Graham, from the Housing Executive, said: "We have been able to find secure, comfortable and well-appointed temporary accommodation.
"It is important we give these families a few days to settle down and consider their own futures."
The attacks have been condemned by Prime Minister Gordon Brown and local politicians.
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