Exiled Tibetan leaders say Beijing's suppression of the rare protests, which began last month, has left about 150 dead.
Chinese officials say only that Tibetan "rioters" left 20 dead.
Insisting that Beijing's handling of the problem was its own affair, Hu said the response was justified.
"Our conflict with the Dalai clique is not an ethnic problem, not a religious problem, nor a human-rights problem," he was quoted as saying.
He was referring to the Dalai Lama, Tibet's exiled spiritual leader.
"It is a problem (of) either safeguarding national unification or splitting the motherland," Hu said.
"The Tibet problem is entirely an internal issue of China.
"No responsible government will sit idle for such crimes, which gravely encroach human rights, gravely disrupt social order and gravely jeopardise the life and property security of the masses."
Earlier on Saturday, China denounced the European Parliament's call to boycott the opening ceremony of the Summer Olympics if Beijing did not begin talks with the Dalai Lama about Tibet.
The European Parliament, in a non-binding resolution adopted by an overwhelming majority this week, called on European Union leaders to consider "the option of non-attendance" of the opening ceremonies of the Games.
Xinhua quoted Jiang Yu, a Chinese foreign ministry spokeswoman, as saying that the European parliamentarians had "rudely interfered in China's internal affairs", "seriously hurt the feelings of the Chinese people", and "confounded black and white".
"The European Parliament turned a blind eye to facts. It did not condemn the Dalai clique who masterminded and organised the violent crimes, but instead emboldened the 'Tibet independence' violence and Dalai's separatist activities," Jiang said.
The Dalai Lama has rejected claims he orchestrated the violence or the protests, and said he supports the Olympics and opposes a boycott of the Beijing Games.
Fortunately for China, the latest leg of the Olympic torch relay, marked by protests in Europe, sailed smoothly through the Argentine capital, under heavy guard on Friday.
The march through Buenos Aires encountered nothing more serious than a few tossed water balloons.
The chaos in Paris, where protesters tried to wrestle the flame from the hands of torch bearers, was still a centre of attention in China on Saturday with the publication of an angry commentary in the People's Daily, the Communist Party's mouthpiece.
It focused on an episode from the Paris relay when a wheelchair-bound Chinese torch bearer fended off protesters.