Family judges across England say they fear being attacked by angry or disturbed parents because security in court is often dangerously inadequate.

It is rare for judges to raise their concerns publicly, but a number have taken the unusual step of speaking out to criticise security at the principal registry of the family division (PRFD) in central London, and also at district courts around the country.

In one incident, a female judge was seriously injured in an attack. Judges also told of parents shouting threats at them, as well as throwing books and cups.

"I have been threatened," one judge told the Guardian, speaking under condition of anonymity. "A very angry father stood up and shouted antisemitic threats at me. Another father threw a cup of water across the courtroom. Another parent threw a book, but fortunately I was too far away for it to reach me."

A second judge, also speaking anonymously, said of the PRFD: "I'm constantly, constantly exposed when I work there. There's no security in the courtroom. None. Sometimes we are in the courtroom alone with a parent. Most commonly, we sit with a clerk, who, in my experience, is always an elderly woman. If anything went wrong, believe you me, she would not be the one defending me.

"We shouldn't have to walk in the public corridors of a building where we have just removed someone's child for ever," the judge added. "At the PRFD, there are no private corridors for judges at all, which means we have to walk through public waiting areas and corridors when moving between courtrooms, entering and leaving the building. We can't even go to the loo without passing through a public area. I feel uncomfortable every time I have to do it. I'm very aware of the constant risk."

A third judge who has worked in the PRFD and courts across London said: "Most district judges, even those doing highly charged family cases, do not have courtrooms at all but hear the cases in their chambers with the public sitting around the table, and they don't have anyone in the court room at all. I have never understood why it is thought that they are less at risk than the higher judiciary."

One circuit judge, who sits in county and crown courts and also in the family division in London, said security arrangements were inadequate. "These are the most volatile, sensitive courts in the land, and one of these days there's going to be trouble in them. The risks are not being addressed properly and unless someone starts considering the security properly then it's a disaster waiting to happen. It will take one serious incident and someone will wake up to the fact that the system is not safe for family judges."

The Guardian has learned of a recent incident when a female judge was seriously injured by an aggrieved parent in the courtroom. The judge has confirmed the violent and deliberate attack but preferred not to give details.

"While it's true that you can't exclude a chance of an attack … the question is whether the essential issue of us judges being hidden away from the public is being complied with, and the answer is, it's not," said a judge who hears cases in the PRFD. "The second question is how protected we judges are when in the courtroom," she said. "The answer to that question is, again, that we're not. The only thing we can do is try to pick out cases with potential violence … and transfer them to the Royal Courts of Justice."

Judges said county courts often do not have a courtroom and a retiring room for district judges. This forces them to hear cases in their chambers, with those involved often sitting uncomfortably close, while the lack of a retiring room means judges have nowhere to go to go if it became necessary to escape an aggressive parent.

"If anything happens, the only place to run is through an adjoining door between my court and that of the other district judge," said a family judge at a court in outer London.

"People blow up in court, of course they do, we're taking their children away. We do have security in my court but they consist of very elderly men and a couple of young girls. The fact that it has not happened so far doesn't mean that it won't."

Another said: "No judge should ever have to sit without a clerk or usher in the courtroom but that is happening all over. It is very bad at the PRFD at the moment."

District judge Nicholas Crichton, founder of the family drug and alcohol court at Wells Street family proceedings court in central London, who was given a CBE in this year's Queen's birthday honours list, said it was a "recipe for flashpoint" to compel judges to walk through public areas and share corridors. Crichton said it was unfair to put anxious parents under the added stress of close proximity with the judge ruling on their case. "Emotions run high. These parents are coming to court feeling criticised about how they treat their children and terrified they're going to have their children removed. That's a pretty toxic mix, but they're not criminals. Everything they have read in the paper and on TV leads them to be frightened of coming to court."

Crichton created an informal regime in Wells Street to reduce the risk of violence. "I'm not going to tell you that we've never had violent incidents here," he said. "We have, but they're few and far between because we have designed a system where parents feel respected from the moment they enter the building."

There are no publicly available statistics for the number of attacks on judges, but a spokesman for the judicial office at the Royal Courts of Justice said: "While we have noticed no recent increase in the level of significant incidents, security continues to be treated as a serious issue. The judiciary monitors security regularly, with input from a broad range of judges in different locations and courts."

A spokesperson from her majesty's courts and tribunals service said: "HMCTS takes the issue of security within courts extremely seriously. Our security system is continually monitored to ensure that it is effective and proportionate and mitigates against risks faced."