Islamabad, Pakistan (CNN) -- A suspected U.S. drone strike in Pakistan's tribal region killed six suspected militants on Monday, intelligence officials told CNN.

Two Pakistani intelligence officials said the suspected drone fired two missiles on a militants' vehicle in the Shawal area of South Waziristan, one of the seven districts of Pakistan's volatile tribal region bordering Afghanistan.

Based on a count by the CNN Islamabad bureau, Monday's suspected drone strike was the 37th this year, compared to 111 in all of 2010.