The Japanese government has announced a 4 trillion yen ($48.9bn; £29.6bn) emergency budget for disaster relief, after March's earthquake and tsunami.

The budget still needs approval from parliament later this month, and could be implemented in May.

Authorities say no new bonds were issued to fund the spending, to prevent adding to Japan's huge public debt.

The government estimates it will cost as much as 25tn yen to rebuild the country.

The emergency budget is aimed at disaster relief, including providing temporary housing, restoration of infrastructure and disaster-related loans.

The 11 March earthquake left more than 27,000 people dead or missing.

It also destroyed infrastructure in the north-eastern part of Japan and triggered a nuclear disaster.

Prime Minister Naoto Kan has said this could be the first of several extra budgets needed to fund reconstruction.

On Thursday, his government made it illegal to enter a 20km (12-mile) evacuation zone around the stricken Fukushima nuclear reactor.

Cooling systems were knocked out by the twin disasters and radiation has been leaking from the plant.

It is not clear how many people are still living in the evacuation zone, but reports said police had counted at least 60 families.

Debt worries

The budget will be financed by taking 2.5tn yen from pension funds, as well as money set aside to increase payments to families with children.

Money from emergency reserves is also being used.

Image caption The devastation has been described as the country's biggest crisis since the end of World War II

But the government has promised that it will not sell more bonds, or borrow more money from the markets, to fund this spending.

Japan already has a debt burden double the size of the economy.

However, some analysts warn that the government will have to increase debt issuances in the future to finance reconstruction.

Controversial cuts

The BBC's Roland Buerk in Tokyo said that although future emergency budgets were likely to require more borrowing, this one would be paid for by spending cuts.

"Plans to increase allowances for families with children are being scrapped and highway tolls will be increased," he said.

"Much of the money will come from dipping into pension reserves, [which is] controversial in a country with a rapidly ageing population.

"Tax rises are also being discussed."

He added that the budget was likely to get through parliament, despite concerns about some of the measures, as the opposition does not want to be seen as preventing money from getting to those who need it.

The government is hoping the budget will be enacted soon, despite calls for Prime Minister Naoto Kan to resign.