President Obama is considering a targeted, highly selective campaign of airstrikes against Sunni militants in Iraq similar to counterterrorism operations in Yemen, rather than the widespread bombardment of an air war, a senior administration official said on Tuesday.

Such a campaign, most likely using drones, could last for a prolonged period, the official said. But it is not likely to begin for days or longer, and would hinge on the United States’ gathering adequate intelligence about the location of the militants, who are intermingled with the civilian population in Mosul, Tikrit and other cities north of Baghdad.

Even if the president were to order strikes, they would be far more limited in scope than the air campaign conducted during the Iraq war, this official said, because of the relatively small number of militants involved, the degree to which they are dispersed throughout militant-controlled parts of Iraq and fears that using bigger bombs would kill Sunni civilians.