Islamabad, Pakistan (CNN) -- A suspected U.S. drone strike in Pakistan's tribal region killed four alleged militants on Friday, intelligence officials told CNN.
Two intelligence officials said the suspected drone fired two missiles on what was believed to be militant hideout in the area of Data Khel of North Waziristan, one of the seven districts of Pakistan's volatile tribal region bordering Afghanistan.
The intelligence officials asked not to be named because they were not authorized to speak to the media.
According to a CNN count, the attack was the fourth suspected drone strike this year.
On Saturday, three U.S. drone strikes Saturday killed 17 people in North Waziristan.
There were an estimated 111 suspected U.S. drone strikes in 2010, and 52 in 2009.
Intense drone activity in Pakistan's tribal region has moved northward, mirroring the movement of suspected militants as they try to flee the targeted strikes, a senior Pakistani military official told CNN.
The United States does not officially confirm that it has unmanned aircraft firing missiles at terror targets in Pakistan, but it is the only country in the region known to have the capability to do so.