Militants fired a rocket at a car carrying UNICEF workers in western Afghanistan on Friday, killing two Afghans and seriously wounding a third, police said. The rocket was fired as the car was traveling to Herat, said Nisar Ahmad Pakar, a district police officer. The driver and a passenger were killed, he said. Another passenger was seriously wounded.Edward Carwardine, a spokesman for UNICEF in Kabul, the capital, said a UNICEF driver, an Afghan UNICEF staff member and a third person from another aid group were in the car. He said the UNICEF staff member was seriously injured and police had informed the U.N. agency that two people were killed. He said he couldn't confirm if either was a UNICEF employee. Carwardine said the attack against the U.N. children's agency was unusual, and that he could not recall any UNICEF fatalities in the last four years in Afghanistan. The UNICEF vehicle was accompanied by another car with armed guards in it, which is standard procedure for UNICEF in Herat province, he said.