Tensions between Angola's president and his long-serving predecessor have erupted into the open as an anti-corruption drive targets the former ruler's family.President Joao Lourenco has pledged to crusade against entrenched state corruption and nepotism since taking over in September from Jose Eduardo dos Santos, who ruled Angola for 38 years.Battling graft is a cornerstone of Lourenco's promised "economic miracle" that he hopes will halt the oil-dependent country's economic slump caused by stubbornly low crude prices.A once-loyal minister under Dos Santos, Lourenco has purged state-run corporations of leaders appointed by his former boss.The first has been Dos Santos's daughter Isabel, who ran the state oil giant Sonangol and is now facing a graft probe.His son Jose Filomeno was similarly dethroned from the top job at the country's sovereign wealth fund in January and was this week charged in relation to a $500m fraud.Dos Santos, 75, who remains head of the ruling MPLA party, has said little on his successor's policies except to caution Lourenco against reforming "too quickly".The former first daughter has not exercised the same restraint and alleged on her social media accounts that her family are victims of a witch hunt at the hands of the country's new leader. On non-speaking terms? Relations "have significantly deteriorated to the extent that both men do not talk to each other," said Alex Vines, an analyst at the London-based Chatham House think-tank."After almost 38 years in power, the transition from Dos Santos to Lourenco was never going to be completely smooth."The state of the economy forced a quicker reform process than originally intended and has had to challenge interests of key members of Dos Santos' family."Angolan media have for several weeks carried reports of a ruction between the two most powerful men in the country.Friction spilt into the open at a meeting of the ruling party's central committee earlier this month when Dos Santos - who previously said he would step down from the MPLA's top job this year - said he may stay on until 2019.According to a member of the committee, there were fierce exchanges between old-guard supporters of Dos Santos and members aligned to Lourenco who want him named party leader immediately.Isabel has waded into the issue, denouncing the spread of "fake news" in the country intended to "create confusion and division at the heart of the MPLA with the intention of destroying it".Lourenco - who served as Dos Santos's defence minister until last year's election - tried to play down any splits at the MPLA gathering, insisting that "such things don't happen on our side". 'Nothing has changed' "Angola is capable of an exemplary transition - right to the end," said social communications minister Joao Melo on his Twitter account in an effort to damp down the political tussle.Journalist Rafael Marques, who was a fierce critic of Dos Santos-era graft, suggested that the disputes was a distraction from Angola's real problems."Nothing has changed. Lourenco's economic team are still using the same old formula which has not done any good for those living in Angola," said the activist who is facing criminal charges for accusing the former attorney general of corruption.Ordinary Angolans are similarly underwhelmed by the direction of the country under the new president."He's been in power for six months but electricity is still as expensive as it was before and people don't have any work," Elisabeth Mateus, 65, told AFP.Vines, the analyst, said that Lourenco was aware that his political future depended on improving living conditions for the population, one of the poorest in the world despite Angola's oil wealth."His principal objective is to have stimulated new economic growth before the next elections in 2022 so that the MPLA be returned with an increased majority," he said.