More than 130 people have been killed and over 300 injured in a twin bomb blast aimed at former Pakistani prime minister Benazir Bhutto.

The explosions went off during a parade in Karachi marking Mrs Bhutto's return after eight years in exile, as she was travelling from the city's airport. The former prime minister herself was not hurt.

Pakistan's President Pervez Musharraf has spoken with Benazir Bhutto and expressed his shock and grief over the attack.

Russia's Foreign Ministry has also condemned Thursday's attacks.

“Russia sympathises with the families of the victims. We condemn this crime against civilians. Russian President Vladimir Putin has expressed his condolences to the Pakistani President Pervez Musharraf. The President said it was a tragic event and called for joint efforts against international terrorism and extremism,” said Boris Malakhov, Russia's Foreign Ministry representative.

So far no one has claimed responsibility.

Pro-Taliban militants angered by Benazir Bhutto's support for the U.S. war on terrorism have threatened to assassinate her.

Benazir Bhutto left Pakistan after General Prevez Musharraf seized power, but returned under a power-sharing agreement that could see her become prime minister again.

Military analyst Evgeny Khrushchev believes Taliban and Al-Qaeda could be behind the act , noting that at the same time, Pakistani President, General Musharraf, could benefit from the bloody drama.