TUNIS — Three police officers were killed in clashes with militants at a checkpoint near Sidi Bouzid in central Tunisia, TAP state news agency reported on Monday. Two police officers died in an attack on the checkpoint and another in a later clash. One militant was killed and another captured, TAP said. Tunisian forces have stepped up their campaign against militant groups since gunmen killed foreign tourists in an attack on the Bardo museum in the capital Tunis in March. No group claimed the Sidi Bouzid attack, but several small brigades of armed groups are active in Tunisia, including Okba Ibn Nafaa, which operates along the border with Algeria. One of its Algerian commanders was blamed by Tunisian officials for orchestrating the Bardo assault. — Reuters