KARACHI (AFP) - Three bomb explosions killed two people including a young girl in Pakistan's port city of Karachi on Saturday, police and hospital officials said, the latest violence ahead of polls next month.

The blasts, two of which targeted secular political parties and another close to a Shi'ite mosque, came a day after a car bomb at a political meeting in the same city killed at least 10 people.

"The first bomb, which was planted near the office of the MQM (Muttahida Qaumi Movement) in Qasba Colony area killed one person and wounded 24 others," local police official Zahid Hussain told AFP.

He said the MQM office was the target but it was not open at the time of explosion, adding that in the second attack a hand grenade was hurled near a Shiite mosque which injured 10 people.

In the third blast, which took place during a campaign meeting of a Pakistan Peoples Party (PPP) candidate in Lyari neighbourhood, a seven-year-old girl was killed and nine others were wounded, police official Muhammad Azim said.

He said that the bomb had been planted on a motorbike.

Police surgeon Aslam Pechuho also confirmed the toll from the three attacks.

The MQM and the Awami National Party (ANP), which was targeted in Friday's attack, were coalition partners in the outgoing PPP-led government and have been threatened by the Taleban.

The three parties are perceived as secular and backed military operations against the Islamists.

As a result of the threats, there have been few large-scale political rallies leading to a lacklustre campaign for the elections.

Amnesty International has also called on Pakistan to investigate the recent wave of attacks, which have resulted in dozens of casualties in different parts of the country, and ensure adequate protection for election candidates.

May 11 national polls should see power pass from a civilian government that has served a full term to another through the ballot box for the first time in the nuclear-armed country's turbulent history.