TUNIS, April 7 (Reuters) - Two Tunisian soldiers were killed and three wounded when Islamist militants attacked a military checkpoint in the southern region of Kasserine, an army spokesman said on Tuesday. Tunisian forces recently killed nine militants belonging to a group officials blamed for orchestrating last month's Bardo museum attack in which two gunmen killed 21 foreign tourists. (Reporting by Patrick Markey; Editing by Hugh Lawson)