Shrapnel hits Joint Chiefs chairman's plane at Afghan base   

• The attack is a reminder "there's no place in Afghanistan that's safe," an analyst says
• Gen. Martin Dempsey was in his room and unharmed
• Two base personnel were slightly injured, and a NATO helicopter also was damaged
• The base comes under attack about twice each month 

Shrapnel from indirect rocket fire Tuesday damaged the plane that had carried the top U.S. military officer to Afghanistan, officials said.

It's a reminder that "there's no place in Afghanistan that's safe," said John Pike, director of GlobalSecurity.org, which tracks security issues.

Dempsey arrived in Afghanistan Monday for meetings with coalition and Afghan leaders, including Gen. John Allen, commander of NATO forces, and Afghan Army Gen. Sher Mohammad Karimi, Dempsey's counterpart in the country.