Sept 18 (Reuters) - At least three people were killed and about 20 wounded in a series of blasts in the eastern Afghan city of Jalalabad on Saturday, two sources in the city said. The fatalities occurred during a series of five blasts, the sources, who said they had received information from hospitals and eyewitnesses, told Reuters. One source said members of the Taliban were among the casualties. The second said the bombs targeted Taliban vehicles. Taliban spokesmen were not immediately reachable for comment. There was no initial claim for the blasts. Jalalabad is the capital of Nangarhar province, which is a stronghold for the Islamic State (IS) militant group that has been active since the fall of Kabul to the Taliban. A series of bombings at Kabul airport on Aug. 26 that were claimed by IS killed more than 180 people. Those attacks were among deadliest during the country"s two decades under U.S. occupation.