Bomb attacks wounded 17 people in Pakistan on Wednesday and targeted an election candidate in the run-up to historic general elections in the nuclear-armed country, police said.

The first attack wounded 13 people near a Shiite Muslim mosque and a private hospital in Pakistan's southwestern city of Quetta, police said.

The bicycle bomb exploded in the Satellite Town area of Quetta, the capital of the oil and gas-rich province of Baluchistan, which borders Afghanistan and Iran.

Police official Fayaz Sumbal said the target was not clear as the injured were mainly bystanders and there was no immediate claim of responsibility.

In the northwestern city of Peshawar, police said another bomb wounded four people outside the home of a local leader in the Pakistan People's Party, which is seeking re-election at the ballot box on May 11 after five years in power.

A third bomb hit the convoy of an election candidate, Israr Ullah Gandapur, seeking re-election as an independent.

Police said the attack happened in the northwestern district of Dera Ismail Khan, but that Gandapur escaped unhurt.

There was no immediate claim of responsibility. The Taliban has directly threatened the outgoing coalition partners, the PPP, the Awami National Party and the Muttahida Qaumi Movement, which are perceived as secular.

Pakistan goes to the polls on May 11 for an election that will mark the first time a civilian government has handed over power at the ballot box after completing a full term in office, in a country used to extended periods of military rule.