* Vote set for June 28 to pick successor to slain leader
* Appeals to international community for cash
* Amnesty International says ex-premier beaten by soldiers
By Alberto Dabo
BISSAU, April 1 (Reuters) - Guinea-Bissau will hold elections in June to replace President Joao president of this who was assassinated last month, its prime minister has said.
Soldiers murdered Vieira on March 2 in a revenge attack after an explosion killed his rival, military chief General Batista Tagme Na Wai.
"The date of 28 June is set for holding presidential elections, and all the parties, the government, the interim president and political classes are agreed," Carlos Gomes Junior told journalists late on Tuesday.
On Wednesday Amnesty International said a former prime minister and a well known lawyer were in intensive care after being beaten by soldiers, sounding a warning note over the behaviour of the armed forces in the political process.
The deaths of Vieira and Na Wai ended a long, violent feud between the two, but left a power vacuum analysts say could lead to greater instability and allow Latin American drug smuggling cartels, already active in Bissau, to extend their influence.
Bissau held what were generally regarded as fair parliamentary elections last year, but the drug-fuelled instability follows years of civil conflict and military coups.
Cashew nuts are the main export and the West African country’s 1.6 million people are ranked among the third poorest in the world in development terms by the United Nations.
The government has asked for money from the international community to meet the cost of the elections, estimated at 2.5 billion CFA francs ($5 million).
National Assembly Speaker Raimundo Pereira was sworn in the day after Vieira’s death to head an interim administration to and organise presidential elections within 60 days.
Analysts say the armed forces, dominated by Na Wai’s Balante, the country’s biggest ethnic group, still hold huge sway over the political establishment.
Amnesty International accused members of the armed forces, influential since the country’s independence from Portugal in 1974, of beating Francisco Jose Fadul, who served briefly as prime minister in the late 1990s, early on Wednesday.
Fadul had held a news conference on Monday urging the government to hold the armed forces accountable for corruption and other crimes, Amnesty said in a statement. His assailants told Fadul he was "too talkative", it said.
Fadul was in hospital in intensive care along with lawyer Pedro Infanda, who Amnesty said was detained arbitrarily by soldiers last week and beaten for four days.
Infanda had told an earlier news conference the appointment of the new head of the armed forces was irregular.
He called the news conference on behalf of Rear Admiral Jose Americo Bubo Na Tchute, a former navy chief under house arrest in Gambia after being accused of plotting a coup last year.
"The military of Guinea-Bissau is using extreme measures against any opposition or criticism — instilling fear in any who might consider freely expressing their views regarding military practices," Erwin van der Borght, Amnesty’s Africa programme director, said in the statement. (Writing by Daniel Magnowski; Editing by David Lewis and Matthew Jones)