Pakistani authorities are yet to make any breakthrough in their efforts to trace Ali Haider, the son of former premier Yousuf Raza Gilani who was kidnapped by heavily armed men in Multan.

“We have not yet received any call from the kidnappers. I ask the ISI (Inter-Services Intelligence) to help the police trace my son,” Gilani told reporters on Friday.

Six to eight armed men kidnapped 27-year-old Ali Haider on Thursday while he was campaigning for Saturday’s national election in Multan district, 350-km from Lahore.

His personal secretary and a bodyguard were shot and killed by the gunmen.

Gialni is one of the top leaders of the Pakistan People’s Party, which led the last government at the centre. The PPP had for long been pressing the Punjab government to take action against the Punjabi Taliban holed up in the southern part of the province.

On Friday it emerged that Ali Haider had received threats from the banned Lashkar-e-Jhangvi and Sipah-e-Sahaba. Though no group has claimed responsibility for the abduction, Gilani and other members of his family told reporters that Ali Haider had been receiving “death and kidnapping threats” from the LeJ and Sipah-e-Sahaba.

Police arrested five suspects in Multan and officials claimed two of them had “important information” about the kidnapping.

The banned Tehrik-e-Taliban Pakistan refused to comment on the abduction. “I do not want to comment (on the incident). We do not know as to who has kidnapped him, and why and how he was kidnapped,” said Taliban spokesman Ihsanullah Ihsan.

The Punjabi Taliban largely comprises members of the LeJ, which also has links with Al Qaeda. The LeJ has been linked to a series of high-profile terrorist acts, including the 2009 attack on the Sri Lankan cricket team in Lahore and two deadly bomb attacks in Quetta earlier this year that killed nearly 200 people, a majority of them Hazara Shias.