Sharif, who had described the killing as the most tragic event in the history of Pakistan, had earlier planned to travel to Larkana in Sindh province to join the funeral at Bhutto's ancestral graveyard in Garhi Khuda Buksh.

But when Sharif spoke to Bhutto's husband today morning on the phone, Zardari advised the Pakistan Muslim League-N chief not to travel to Larkana in view of security concerns, sources from Bhutto's Pakistan People's Party said.

Zardari told Sharif that his presence could aggravate the tense situation in Larkana, the sources said.

PPP workers have already staged violent protests in Larkana, vandalising and burning government offices, cars and trains. Over fourteen people have reportedly died in the violence so far.

Reports said that Sharif would travel to Larkana later to express his condolences to Bhutto's family. The former premier was gunned down by a suicide attacker in Rawalpindi on Thursday evening.

Sharif has decided to boycott the January 8 general election in the wake of Bhutto's assassination.