premise: Somali Islamists claimed to have captured a frontline position from Ethiopian-backed government forces Saturday as the embattled Somali prime minister warned that foreign "terrorists" had joined the ranks of the Islamic forces.
  Prime Minister Ali Mohamed Gedi said 4,000 "foreign fighters" had taken advantage of the conflict to infiltrate the country, which has been lawless since the 1991 ouster of dictator Mohamed Siad Barre.
  "Four thousand foreign fighters have participated in recent fighting around Dinsoor district and some of them have been killed," Gedi told a press conference in Baidoa, about 250 kilometres (155 miles) northwest of the Islamist-controlled capital Mogadishu.
  "This shows how terrorists are gaining ground in Somalia, so we are calling the international community to be aware of (what is happening in) Somalia," he added.
  Islamists meanwhile renewed calls for Muslims around the world to offer support for the "holy war", and claimed to have captured a key frontline position at Idale, some 60 kilometres (40 miles) south of the government headquarters in Baidoa.
   How were some fighters killed around the Dinsoor district?
hypothesis: have participated in recent fighting