South Sudan's army said it had lost contact with its troops in the key oil hub of Malakal following a major offensive by rebels. The rebels have said they **w control the **rtheastern town after launching an assault on Tuesday, prompting the US to de**unce a "blatant violation" of a ceasefire agreement signed in Ethiopia last month. "I have ** contact with the command in Malakal," army spokesman Philip Aguer told AFP, as the independent radio Tamazuj said a top government general had been seriously wounded in an attack reportedly involving tens of thousands of rebel fighters. "We are in ** position to confirm who is in control of Malakal town because our people have **t been able to get into town," said Joe Contreras, spokesman for the UN mission in South Sudan (UNMISS).