A suicide bomber detonated a car packed with explosives near a NATO base in Kandahar in Afghanistan's south on Thursday December 13, killing two people and wounding 16, including three foreign troops, police said, according to Reuters.

U.S. Defense Secretary Leon Panetta, who arrived in Afghanistan on Wednesday, was in Kandahar before the blast.

Panetta met top commanders in Kabul to finalize options for President Barack Obama on how many troops to keep in Afghanistan after the NATO mission ends in 2014.

Panetta has not disclosed how large a force he believes will be needed, but one U.S. official has told Reuters that figures as low as 6,000 U.S. troops were under consideration. Obama could make a decision in the coming weeks.