(Reuters) - "Welcome Home Benazir Bhutto". The message on hoardings looming over Karachi's streets seemed to possess a chilling sub-text a week after the suicide attack that killed 139 people during what was supposed to have been Bhutto's triumphant homecoming.
The ensuing security scare means former prime minister Bhutto has not left Karachi since, although her aides said on Thursday she would visit her ancestral home near the city of Larkana in the north of Sindh province over the weekend.
Hundreds of thousands of supporters came out to greet Bhutto on her return from eight years of self-imposed exile, and she will expect another big turnout in the family's feudal fiefdom, regardless of the assassination threat against her.
On Thursday a new officer took charge of the investigation into the suicide attack by at least one bomber, possibly two, after Bhutto complained that the policeman originally appointed had been present when her husband Asif Ali Zardari was tortured while in custody in 2000.
Government officials have blamed the attack on Islamist militants based in tribal areas where al Qaeda and Taliban fighters operate near the Afghan border, but Bhutto has said influential members of the Pakistani establishment are also out to get her.
A statement issued by her Pakistan People's Party (PPP) suggested that the head of one of Pakistan's security agencies, Intelligence Bureau Chief Ijaz Shah, was one of the people Bhutto had named in a letter to President Pervez Musharraf.
Bhutto, whose PPP is the largest opposition party, again expressed her dissatisfaction with the conduct of the investigation, repeated a request for foreign experts to be involved in the probe along with demands for better protection.