( AFP ) - Former Pakistani premier Benazir Bhutto visited a hospital to meet those injured in last week's devastating suicide attack that turned her homecoming parade into bloody carnage.
Bhutto was flanked by heavy security carrying automatic weapons as she made her first public outing since Thursday's blasts in Karachi, which killed 139 people and ruined her planned triumphant return after eight years in exile.
Bhutto waved to dozens of supporters as she left Jinnah Hospital, where she also met with doctors treating those injured, but did not make a public statement, an AFP correspondent at the scene reported.
Bhutto has pledged since the attack, the worst in Pakistan's history, to stay to combat militancy and fight general elections in January, seen as a key step to returning the country of some 160 million people to civilian rule.
Her hospital visit came as police questioned three people over the attack, which sparked a third straight day of protests Sunday by her supporters in several cities in southern Pakistan, officials said.
The three suspects were linked to a car from which an attacker threw a grenade into the hundreds of thousands of people who gathered to greet Bhutto's convoy, a police official said.
Seconds later a suicide bomber blew himself up in the massive crowd, which had gathered to see Bhutto just hours after the two-time premier stepped foot on Pakistani soil for the first time since 1999.
Police have also quizzed seven militants in jails in Karachi for possible information on the blasts, added the official, who has investigated several other attacks in the volatile port city.
Bhutto's aides on Sunday handed in an official crime report on behalf of their leader, asking police to "investigate so that the accused and their conspirators may be brought to book and punished according to the law."
"The dastardly attack was aimed at my physical elimination and elimination of the top leadership of the party and devoted selfless supporters in an attempt to derail the democratic process," it said.
"We have not been kept informed on any progress on this investigation," senior party member Sherry Rehman told Dawn television.
Around 10 groups of protesters, each of around 50 people, burned tyres and hurled stones in a stronghold of Bhutto's party in Karachi, while streets elsewhere were deserted, an AFP correspondent said.
Similar protests were staged in the cities of Hyderabad, Nawabshah, Sukkur and other districts that were home to some of the bombing victims, officials said.
"There are reports about mild protests and burning of tyres in different districts but all these are largely peaceful," Sindh province home secretary Ghulam Mohammad Mohtarram told AFP.
Mohtarram said authorities were still investigating the blast "but no clues are yet available to proceed on," adding that he had no information about the people being questioned.
Bhutto has said she received a warning prior to her return from Dubai about members of the Al-Qaeda network, Pakistani and Afghan Taliban and a Karachi-based militant group who might have been planning to attack her.
She has also accused Islamist supporters of late military ruler Zia-ul-Haq of being behind the blasts. He overthrew Bhutto's father, prime minister Zulfiqar Ali Bhutto, in 1977 and had him hanged two years later.
The attack on her motorcade has cast doubt over her previous plans to tour the country to whip up support ahead of the crucial January polls.
Her party said she would soon visit the tomb of her father in her family's ancestral village of Larkana after consultations with senior party leaders at her home in Karachi.
Bhutto had returned from self-imposed exile after President Pervez Musharraf dropped corruption charges against her in the hope her popularity could shore up his grip on power.
She had mostly worked out a power-sharing deal with him, but his re-election as president earlier this month is now being challenged in the courts, as is the graft amnesty.