Supporters of Pakistan's former Prime Minister Benazir Bhutto are expressing outrage over the twin explosions that killed at least 125 people and wounded scores of others during her homecoming parade in Karachi Thursday. VOA's Barry Newhouse reports from Islamabad that supporters are saying government officials might have been involved.

The Pakistan government had promised "foolproof" security for former Prime Minister Benazir Bhutto's homecoming.

But Senator Latif Khosa of Ms. Bhutto's Pakistan People's Party says electronic bomb jammers operated by the police near her motorcade did not appear to be working.

Security officials say they suspect a suicide bomber was responsible for the main blast, and it is difficult guard against such an attack.

Khosa, however, says even before Ms. Bhutto's arrival, she suspected at least two people in the government were plotting an attack against her.

"The former prime minister had already written a letter to the president of Pakistan nominating certain people who in her estimation would be responsible for the attack in case it so happened - and it has ultimately happened," said Khosa.

No officials were immediately available to comment on this claim.

Witnesses say security was tight at the start of Ms. Bhutto's procession near the airport in Karachi. But they say the security cordon around her vehicle grew lax after making its way for several hours through crowds of her supporters, estimated at 150,000 or more.

Senator Khosa says he was riding behind Ms. Bhutto's armored vehicle when gunfire rang out, and then two explosions thundered in quick succession.

The Karachi police say the first explosion was from a grenade, and the second was a suicide bomb.

Khosa said Ms. Bhutto had left the unprotected roof of her armored truck just minutes before the blasts tore through a crowd of people near the vehicle.

"It was the human shield surrounding her that unfortunately lost their lives," he said.

Ms. Bhutto appeared shaken, but party officials say she was unhurt in the attack. The party vowed that her planned homecoming journey across Pakistan will continue.