Police in Indonesia say they have found half a ton of ammonium nitrate, a material used in the Bali bombings.

It is the second such find in recent days.

The chemical, which is used mainly as a fertilizer, was found in a house in Palu, on Sulawesi island.

A week ago, police seized 250 kilograms of ammonium nitrate in a car in Palu. Five people were arrested after that discovery, although they are still looking for the owner of the fertilizer.

Ammonium nitrate can be used as a powerful explosive when mixed with fuel oil, although it is often used by local fishermen.

The owner of the house where the latest cache of the fertilizer has been found is being questioned.

The find could be linked to clashes between between Muslims and Christians in central Sulawesi, which have resulted in the deaths of almost 1,000 people over the past two years.

Bali link

But police say ammonium nitrate was also used to make the two bombs which blew up nightclubs in Bali on 12 October.

Police hope to bring the Bali suspects to trial in February

A ton of another chemical they say was used in the attacks, potassium chlorate, was seized from a house in East Java in mid-December.

Police said they found 40 sacks of the chemical, which is used in fireworks and can be used for making bombs, during a raid on a house in Banjar Wati.

The house belongs to a friend of Amrozi, under arrest for his part in the attacks, which killed over 180 people.

Chief investigator into the Bali bombing, I Made Mangku Pastika said on Monday that police were planning to hand the files on Amrozi to prosecutors next week.

Prosecutors will then prepare formal charges against Amrozi, whom police say has admitted to helping buy explosives for the bombing, and to owning the van used in the attack.

Police have said they expect the first suspects in the case to be tried by February.