Obama administration says 64 to 116 civilians killed in drone strikes, but rights groups are skeptical

After escalating one of the most lethal covert operations in U.S. history, President Obama finally made a public estimate of the civilian cost of the nation's secret drone program, which has targeted Islamic militants in remote corners of the globe. Human rights groups immediately challenged the estimate and the amount of transparency from the administration, saying both were too limited. The White House said that 64 to 116 civilians had been wrongly killed in 473 strikes launched by the U.S. government from the time Obama was inaugurated and the end of last year. The vast majority of the attacks were launched by drones, officials said, but the estimate also covers some strikes using manned aircraft. Monitoring organizations estimate the number of civilians killed in U.S. strikes ranges from 200 to more than 1,000.