MOGADISHU, Somalia -- A powerful Islamist group linked to al-Qaida on Wednesday ordered two radio stations in southwestern Somalia to stop broadcasts indefinitely. Al-Shabab delivered letters to Jubba and Warsan Radio stations early Wednesday ordering the shut down without giving any reasons, said Mohamed Adawe, a journalist with Jubba Radio. Another Jubba Radio journalist, Abdikarin Jakarta, said the letters threatened the stations with unspecified action if they disobeyed the closure orders.