Twin bomb explosions on Saturday killed one person and wounded 19 others in Pakistan's port city of Karachi, police and hospital officials said, the latest violence ahead of polls next month.
The blasts, one targeting the office of a secular party that dominates the commercial hub and another close to a Shiite mosque, came a day after a car bomb at a political meeting in the same city killed at least 10 people.
"According to our initial investigation, the first bomb, which was planted near the office of the MQM (Muttahida Qaumi Movement) in Qasba Colony area wounded 15 people," local police official Zahid Hussain told AFP.
He said the MQM office was the target but it was not open at the time of blast, adding that in the second attack a hand grenade was hurled near a Shiite mosque which injured up to four people.
Another police official, Bilal Khan also confirmed the incident.
The two policemen were unable to confirm any deaths but a senior doctor in Abbasi Shaheed hospital said they had received one dead body after the attacks.
The MQM and the Pashtun-dominated Awami National Party (ANP), which was targeted in Friday's attack, were coalition partners in the outgoing Pakistan People's Party (PPP) government and have been threatened by the Taliban.
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.