Prime Minister Kevin Rudd has urged against vigilante action in the wake of a string of violent attacks against Indians in Sydney and Melbourne.

Yesterday police had to move on groups of Indian men who were patrolling Melbourne railway stations in a bid to prevent more attacks.

And for a second night in a row Indian students took to the streets of Sydney last night to protest against what they say is a lack of police protection in the wake of two assaults.

Last night about 70 young men blocked off an intersection at Harris Park. Two men were arrested; one was later released without charge and the other was served a notice to appear in court later this month.

Mr Rudd has put students considering retaliating against the attacks on notice.

"It's unacceptable for any student group to believe they can take the law into their own hands and engage in so-called retribution attacks or vigilante action," he told 3AW radio.

Many Indian students are angry for what they describe as inadequate protection against racially-motivated attacks.

But Mr Rudd has called for calm and says Australia is one of the safest countries in the world.

"I think everyone just needs to draw breath on this and I think we need to see a greater atmosphere of general calm," he said.

"All cities from time to time are going to have acts of violence. I'm advised on the statistics [that Australia] is one of the safest countries in the world for international students."

Mr Rudd says balance needs to be restored to the debate, adding Australians have been victims of crime when they visit India.

"In the last decade I was advised we had, I think, up to 20 Australians who had either been murdered or had various forms of assault committed against them," he said.

"That is not the result of Australians being targeted in India, that's just a fact of violence in cities around the world, so I do think we need some balance in this debate."

Deputy Prime Minister Julia Gillard has been confronted by a group of international students demanding the Government do more to protect them.

The students were protesting at the University of Sydney, where Ms Gillard was launching a program to encourage enrolments by disadvantaged people.

Ms Gillard spoke to the students to hear their concerns and says the Government is working to address the issues.

Call for calm

India's Foreign Minister, SM Krishna, has urged Indian students to stay calm in the wake of the attacks on them.

"I would like all Indian students to be patient," he said.

"They should be restrained. They have gone there to pursue higher studies and they should concentrate on that, rather than retaliate."

Foreign Affairs Minister Stephen Smith has also urged restraint, saying state and federal authorities are doing all they can to make sure foreign students are safe.

"I simply echo the comments of my Indian counterpart. The time has now come for restraint. The time has come for calm," Mr Smith said.

"People should simply let the police authorities get on with their jobs. We know that both in Victoria and New South Wales those relevant authorities are working very hard on this."