The interim government, which took over after Bakiyev was ousted by a public revolt in April, has been unable to stop the violence and accused Bakiyev's family of instigating it. Uzbeks have backed the interim government, while many Kyrgyz in the south have supported the toppled president.
From his self-imposed exile in Belarus, Bakiyev denied any role in the violence and blamed interim authorities for failing to protect the people.
Interim President Roza Otunbayeva's government had hoped to seal its political and democratic credentials in a referendum to approve a new constitution on June 27, but the likelihood of that vote taking place now looks slim.
A government order for troops to shoot rioters dead failed to stop the spiraling violence. Police and the military appeared to be on the defensive across the south, avoiding clashes with mobs. Flights to both Osh and Jalal-Abad were canceled and the airports were closed.
In Jalal-Abad on Sunday, thousands of Kyrgyz men brandishing sticks, metal bars and hunting rifles marched together to burn Uzbek property while frightened police stayed away. Uzbeks felled trees on the city's main street, trying to block their advance.
Kyrgyz mobs tried to storm the city's hospital, but Uzbeks drove them off after a fierce gunbattle that raged for hours, witnesses said. Mobs also surrounded a local prison, trying to free its inmates, and attempted repeatedly to capture the Jalal-Abad police headquarters, but were repelled.
Kyrgyz mobs killed about 30 Uzbeks on Sunday in the village of Suzak near Jalal-Abad, said Talaaibek Myrzabayev, the chief military conscription officer in the capital, Bishkek. Another Uzbek village, Dostuk, was burned by Kyrgyz assailants, but it was not known how many people were killed, he said.
Ethnic Uzbeks ambushed about 100 Kyrgyz men Sunday on a road near Jalal-Abad and took them hostage, Myrzabayev said. Vehicles on the main highway near Jalal-Abad repeatedly came under fire from unidentified gunmen. Later in the day, troops were seen shooting at the gunmen.
In the nearby village of Bazar-Kurgan, 400 Uzbeks overturned cars and killed a police captain, local resident Asyl Tekebayev said. Residents said armed Kyrgyz men were flooding into the village to retaliate.
The official casualty toll Sunday rose to at least 104 people killed and 1,231 wounded, the Health Ministry said. The ministry said this included 21 dead in the main hospital in Jalal-Abad but not hospitals elsewhere in the region.