By Andrew Harding
BBC News, Singapore
Singapore says it is looking for new sources of sand after giant neighbour Indonesia announced an export ban.
Singapore's booming construction sector uses a lot of sand
Jakarta announced the ban last month amid claims that Singapore was in effect stealing its territory.
For years tiny, wealthy Singapore has been importing huge amounts of sand, for building and for an ambitious scheme to reclaim land from the sea.
Indonesia argues some of its islands are disappearing as a result, dug up and shipped wholesale to Singapore.
The Indonesian authorities have banned sand exports and restricted the trade in granite chips.
The authorities here say they are confused and disappointed.
But Singapore has got plenty of sand stockpiled and will now look elsewhere for raw materials.
Singapore is used to this sort of row with its bigger, better resourced neighbours.
It has often had run-ins with Malaysia over water supplies.
There are suspicions that Indonesia may be using the dispute to put pressure on Singapore over an extradition treaty it is negotiating.
But there is another issue at stake.
If Singapore continues to reclaim land and grow in size, what will happen to its maritime borders?
Singapore insists they will not change. Its neighbours are not so sure.