The authorities in Malaysia say they have arrested five men linked to the Indonesian Islamic militant organisation that some governments suspect of involvement in Saturday's bomb attack on Bali.

Police said all five were connected with Jemaah Islamiah, and at least one of the men was also connected to the al-Qaeda network of Osama Bin Laden.

Norian Mai, chief of Malaysia's police force, announced the arrest of four of the men, saying they were not connected to the Bali attack. A fifth man was arrested later on Wednesday.

The police chief said the arrests were planned before the weekend bombing, which killed at least 180 people on the holiday island.

The detentions were said to bring the total number of suspected Islamic militants detained in Malaysia since last November to 72.

'Jeopardised security'

Speaking about the first four arrests, Mr Norian said the suspects - all Malaysian - were "planning something for the interest of their organisation", and that they had been involved in attempts to threaten national security.

He did not give details.

Mr Norian said the men, arrested in several different Malaysian states on Wednesday, were not key leaders of Jemaah Islamiah (JI) but "they play an important role in each state".

He also said they had been in contact with militants in neighbouring countries.

JI is thought to want to establish a pan-South-East Asian Islamic state.

Asked how many JI members remained at large in Malaysia, Mr Norian said: "There are just a few more."

The Malaysian Prime Minister, Mahathir Mohamad, has won praise from Washington for his effort to crack down against suspected militants following the 11 September attacks on the United States.

All the militant suspects apprehended are being held under a security law which allows for indefinite detention without trial.