JAKARTA, July 31 (Xinhua) -- Police are still in the dark over the identities of the perpetrators who committed suicidal bombings at J.W. Marriott and Ritz Carlton hotels on July 17 despite information filed in by the public, Indonesian police spokesperson said here Friday.

"We are now expecting more valid information about the men whose sketches we already distributed to the public. So far there is no information about those men," Nanan Sukarna told a press conference at the police headquarters.

Nanan was disclosing the police's effort in seeking information about the perpetrators from the public by distributing the photos of their heads that remained intact.

Besides that, police also distributed the photos of Nurdin M. Top, the leader of the terrorist group that allegedly masterminded the bombings, to the public.

Nanan was optimistic that the identification of the bombers would be revealed in the near future as police were able to do so in less than two months in the previous bombing cases. 　

"The longest period to reveal the bombers' identification was 41 days," Nanan was quoted by the Detik.com as saying.

Based on the evidence the police gathered from J.W. Marriott hotel, police learned that the suicidal bomber was a man at an age range of 20 - 40 years old, while the Ritz Carlton man at an age range of 17 - 20 years old.

Police's earlier identification on Nur Hasby, alias Nur Sahid, a man who allegedly did the bombing, apparently failed as the DNA of the man's parents did not match.