MOGADISHU, Somalia (AP) — Somalia's Islamic extremists, al-Shabab, appear to be making a comeback, having recently seized four towns and attacked a guesthouse in neighboring Kenya, killing 12. Al-Shabab's swift seizures of the newly exposed towns are worrying for Somalia, which faces a presidential election in late November. "Returning a large number of troops back home left the Ethiopian army overextended in Somalia, so abandoning some ground in Somalia is inevitable," said Mohamed Sheikh Abdi, a Somali political analyst. [...] Somalia's civilians are bearing the brunt of the withdrawals, with militants executing suspected government collaborators in each location they recapture, say residents. Somalia's security forces are supposed to be taking on more responsibility as the African Union force prepares to withdraw by the end of 2020, but this month's attacks indicate that the Somali forces may not be able to hold the gains made by the African Union troops that deprived al-Shabaab of large parts of territory.