The restrictions, limiting individual purchases to 5kg, came into force yesterday, even as KL issued assurances that shortages would be resolved within a few days and that prices would not rise.

Prime Minister Abdullah Badawi said there is enough cooking oil in the country, despite reports of supermarket shelves running bare.

He said the shortage involved only cooking oil sold in small packets subsidised by the government, and resulted partly from increased demand over the festive season.

The problem was exacerbated by panic-buying, hoarding, and smuggling to neighbouring countries where cooking oil costs more, he said.

'The supply of subsidised cooking oil will return to normal in a few days, and rationing will be lifted.

'The government has decided not to raise retail prices,' said PM Abdullah.

Panic buying had gripped several states after people found it hard to get cooking oil over the last week.

The rush was fuelled by rumours that prices were about to rocket in line with record global crude palm oil prices.

PM Abdullah also announced a ban on subsidised cooking oil being taken out of the country, and said border checks were being stepped up.

But despite the prominent signs displayed in Johor supermarkets warning that only local people could buy palm-based cooking oil and threatening action against non-domestic users, enforcement appeared to be lax yesterday.

A Straits Times reporter witnessed a free-for-all as shoppers snatched up bottles, and observed that there were few checks at immigration and customs checkpoints.

Government assurances are doing little to calm Malaysians' fear of shortages.

The Star reported yesterday that hawkers in Penang are making several trips a day to buy cooking oil.

And the Mydin Mall in Kuala Terengganu yesterday said it has actually been selling more oil since rationing was imposed, up from four to five tonnes a day.

At the same time, many customers were complaining that they could not find palm oil, and were forced to buy canola or corn oil instead.

The Star quoted 33-year-old secretary Rubi Isni Zainuddin as saying: 'These are more expensive, but we have no choice.

'We have to buy what's on the shelves as we still need to cook.'

carolynh@sph.com.sg