Witnesses in Yemen's southern port city of Aden say angry protesters set fire to the municipal building and a third demonstrator has been killed as protests stretch into an eighth day.

Hundreds of protesters demonstrated in the country's second largest city until early hours Friday demanding the ouster of the president, a key U.S. ally in battling al-Qaida.

A call spread by Facebook and Twitter is urging Yemenis to join a series of "One Million People" rallies on a so-called "Friday of Rage" in all Yemeni cities.

Protesters are demanding the ouster of President Ali Abdullah Saleh, in power for 32 years.

In Taiz, Yemen's second largest city, thousands of government supporters took to the streets Friday ahead of expected afternoon protests.