Washington ? The global shipping industry should consider placing armed guards on its boats to ward off pirates who have become increasingly violent, the U.S. military commander who oversees the African coastline said Friday.

Gen. David Petraeus, who came to the Capitol to talk about a wide variety of issues, told a House committee Friday that just trying to outrun or block pirates from boarding cargo ships isn’t enough to deter sea bandits off the Somali coast who are becoming more aggressive. The Pentagon is starting to study how to better protect merchant shipping, but hasn’t yet come up with a formal plan.

The shipping industry has resisted arming its boats, which would deny them port in some nations.

In response to questions from a House Appropriations subcommittee, Petraeus said defensive preparations short of armed guards “can work. You can have water hoses and others that can make it more difficult.”

But in a wry tone, he added: “It’s tough to be on the end of a water hose if the other guy is on the end of an RPG. So you’ve got to think your way through that calculation as well.”