A string of explosions struck Kandahar in southern Afghanistan Saturday, killing at least 35 people and wounding another 45, local authorities said.

The death toll is expected to rise.

"There were four suicide bombers," Mohammad Pashtun, chief of criminal investigations for Kandahar province, told The Los Angeles Times by telephone, "including two in cars, and all the attacks happened within the city (of Kandahar, the provincial capital) about 7:30 p.m. (local time). Thirty-one people have been killed and at least 45 are wounded. They are all civilians."

Rescue crews searched toppled buildings for the dead and wounded, the report said, and hospitals quickly filled up.

Kandahar is a Taliban stronghold.

CNN reported the terror attacks came after the top U.S. general in the country pledged coalition forces "are absolutely going to secure Kandahar."

Gen. Stanley McChrystal told reporters Tuesday a military operation could begin in the province as early as this summer, but he warned that much political groundwork lay ahead.

McChrystal said a "menacing Taliban presence" is part of a larger counterinsurgency in southern Afghanistan.

Provincial Gov. Toryalai Wesa confirmed Saturday's blasts hit four sites, CNN said. One explosion struck near the police headquarters in Kandahar; another near the province's prison, and a third explosion caused the collapse of some residences.

NATO-led coalition forces in Kandahar were not targeted, the military said in Kabul.