Four strikes on Saturday killed 34 militants and another two on Sunday killed 28, the US Africa Command said in a statement.

The air attacks, in a coastal region south of Somalia's capital, Mogadishu, were the deadliest in the country since November last year when the US said it had killed 100 militants.

All six airstrikes were "conducted to prevent al-Shabab from using remote areas as a safe haven to plot, direct, inspire, and recruit for future attacks," the statement said.