SSP says several suspects, including a police official and a doctor, have been detained, DNA samples of key suspects' brothers and father collected.
Mahar, a senior journalist associated with a private Sindhi newspaper, was shot dead while he was travelling in his car on Sunday.
Says investigation is under way, initial inquiry report to be ready in 48 hours; asserts "those responsible will be punished".
Railways minister constitutes team to probe incident.
Party loyalists and supporters gather outside jail to welcome PPP leader.
Train service on affected tracks restored after almost 30 hours.
Between 15 to 20 passengers are still trapped in the wreckage of the Millat Express train, says Ghotki SSP.
Sukkur DC says the vehicle turned turtle due to speeding.
Police said he was wanted for multiple serious crimes in various districts of Sindh.
Officials say all people travelling on the train have been rescued; inquiry under way to ascertain cause of derailment.
Sohail Anwar Siyal says the house raided by NAB's team belonged to his late father.
The suspect is the head of the family; victims include six women and five children.
Members of religious group disrupt Aurat March in Islamabad, situation brought under control by police.
Sukkur Police AIG says more casualties feared as several injured are in critical condition.
Death toll rises to 6; five others also pulled out from the rubble in a wounded state.
Officials say several people are still feared to be trapped under the rubble; rescue operation underway.
PPP leader tells journalists to "investigate" allegations against him.
A case was registered by police against the suspect who leads prayers at a mosque in Dildar Samejo village.
JUI-F Punjab chief Maulana Attiqueur Rehman welcomes the participants of the march.
'Azadi March' to kick off in Karachi on October 27 after address by JUI-F chief in Sohrab Goth.