Indonesian anti-terror police hunting two Malaysian bombmakers have hit an impasse after four men seized in an intense dragnet operation were released due to lack of evidence, a report said today.

National police spokesman Inspector General Paiman told journalists that the four, arrested earlier this week by police searching for Malaysians Noordin Mohammed Top and Azahari Husin ( photo, left ), were cleared of links to the suspected bombers.

"There was no proof they were involved, directly or indirectly with the two people we are looking for," Paiman said at his office late on Tuesday, in comments broadcast on Elshinta radio.

Noordin and Azahari are believed to have masterminded the Sept 9 bomb attack on the Australian embassy in Jakarta in which 10 died. They have also been linked to the Bali bombings and last year's Jakarta Marriott hotel blast.

Further attacks

Police have warned the two have been recruiting for further attacks on Western targets in Indonesia.

Paiman said the four detainees had been returned to their homes on the central island of Java. He said they had admitted taking part in "training", but this was related only to "battling crimes".

Reports at the time of the arrest of the four said the men were suspected of links to a blast at a rented house in Sukabumi, west Java, last month in which one person was injured.

Detectives said that incident offered clues to the whereabouts of Noordin and Azahari.

They have dispatched 3,000 police to trawl the west Java area, which they say is a fertile recruiting ground for the Malaysians who have been linked to the Jemaah Islamiah extremist group blamed for Bali and other attacks.