Gunmen attacked a passenger bus in central Somalia Monday, killing one person and wounding five others, witnesses said. Passengers said the shooting began after the driver refused to pay an illegal tax at a checkpoint occupied by the gunmen, the Shabelle Media Network reported. Attacks on civilian buses by gunmen who want to rob passengers have increased in recent weeks, police said. Authorities said the extremist group al-Shabaab was involved in two separate attacks Sunday. One attack was against the barracks of Somali government forces in the Hosh neighborhood of southern Mogadishu. Scores were said to have been wounded. In the other incident, attackers hit a government compound in the Yaqshid district north of Mogadishu. The overall casualty toll among government forces was uncertain. No civilians were reported killed or injured in either of the attacks.