Islamabad, Pakistan (CNN) -- A suspected U.S. drone strike in Pakistan's tribal region on Wednesday killed 23 suspected militants, intelligence officials told CNN. Two Pakistani intelligence officials said the suspected drone fired four missiles at a militant training center in the area of Roya Naray in 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 said they are not authorized to speak to journalists. Based on a count by the CNN Islamabad bureau, Wednesday's suspected drone strike was the 32nd this year. CNN's Nasir Habib contributed to this report .
Suspected drone attack is in volatile North Waziristan . There have been 32 suspected drone strikes in 2011 .