At least seven members of parliament have resigned in Yemen to protest over government violence against demonstrators.

Witnesses say at least two protesters were killed and a dozen injured on Tuesday when government forces opened fire on demonstrators during a sit-in in front of the university in the capital Sanaa.

Inspired by the overthrow of life-long leaders in Tunisia and Egypt, protesters in Yemen have been demanding an end to the rule of President Ali Abdullah Saleh after 32 years.

Saleh is an ally of the United States in the fight against a Yemen-based al Qaeda wing that has launched attacks at home and abroad.