MOSCOW. Dec 5 (Interfax) - Several people have been arrested on suspicion of involvement in murder of journalist Anna Politkovskaya in 2006 and a 2007 train bombing but it is too early to say the two crimes have been solved, Dmitry Dovgy, head of the Chief Investigation Department of the Russian Prosecution Service Investigation Committee a senior criminal investigator said in an interview to be published in Rossiiskaya Gazeta on Thursday.

"It is premature to speak of the complete solution of (Politkovskaya's murder). The entire chain from those who commissioned it to those who executed it has not been found out yet," Dovgy told the daily.

Some people have been arrested and charged in the course of the investigation of this crime, he said.

"I will not disclose the details of the investigation. But I am sure that we are on the right track and have moved quite a way ahead in investigating this case," Dovgy said.

Asked whether the investigators knew the names of those who commissioned and executed the murder, Dovgy said he had "No comment for the time being."

As for the bombing that derailed a Moscow-St. Petersburg train last August, "one cannot speak of complete solution either," Dovgy said.

The entire chain of perpetrators of this crime had not been found out either, he said.

Brothers Maksharip and Amirkhan Khidriyev had been arrested and charged with terrorism in connection with the attack, Dovgy said.

"The investigators have enough evidence, but we are continuing our investigation. And, whereas initially we were working on several theories behind the bombing of the train, today they have gone down in number," he said.

Dovgy was asked to comment on statements by some officials that the two crimes have been solved.

"The Investigation Committee has never made any such statements, and I believe that premature statements of this kind are simply harmful, especially when they are widely propagated by the media," Dovgy said.

"Law courts alone have the right to establish whether the accused are guilty. And they may see this as pressure from the prosecution service and the press," he said.