Yemen's ambassadors to Saudi Arabia, Kuwait, Egypt, Indonesia, India, Algeria and Spain defected on Monday to join the rapidly growing protests demanding ouster of President Ali Abdullah Saleh, an official of the Information Ministry told Xinhua.

Scores of senior government officials, ambassadors, top security and army officers and tribal leaders declared on Monday to join the protesters and support their demands of peaceful power transition.

Government's official resignations were geared up by a string of violent acts against protesters, the latest of which was Friday 's shooting that claimed the lives of 52 people in the capital of Sanaa, the ministry's official said on condition of anonymity.

Meanwhile, the U.S. embassy in Sanaa urged its citizens on Monday to stay indoors due to instability in Yemen, according to a travel warning.

"Due to continued political instability and uncertainty in Sanaa and the rest of Yemen, the U.S. Embassy urges all U.S. citizens in Yemen to remain indoors this evening," the warning said.