Venezuelan officials say some seven people were injured, including at least two by gunfire, after unidentified assailants opened fire on university students returning from a protest against President Hugo Chavez's planned constitutional changes.

The violence erupted at the Central University of Venezuela on Wednesday after thousands of university students marched to the Supreme Court to demand it postpone a referendum on constitutional changes that would expand the president's power.

In a national address, Interior Minister Pedro Carreno asked university officials to restore order. He also accused the media of broadcasting biased news and fomenting hatred.

The constitutional changes would eliminate presidential term limits, further Mr. Chavez's socialist reforms and strip the central bank of its autonomy. They also would give authorities sweeping powers if a national emergency is declared, including detention without charges and controls on the news media.

Venezuela's opposition parties, human rights groups and the Roman Catholic Church have condemned the plan. Former Venezuelan Defense Minister Raul Baduel says the changes would amount to a coup d'etat by Mr. Chavez.

Some information for this report was provided by AFP, AP and Bloomberg.