Clashes between troops loyal to Yemeni President Ali Abdullah Saleh and opposition forces have killed at least three people in the capital, Sana'a.

Medics said those killed in Monday's fighting were in the city's Change Square, which has served as a center of anti-government protests. At least six people were wounded in other parts of Sana'a.

The clashes come a day after loyalist forces shot at protesters in the capital, where activists say tens of thousands of people gathered to call for the president's resignation. Snipers on rooftops are reported to have killed four people Sunday, while security forces in the southern city of Taiz killed one person.