A roadside bomb wounded at least 10 people Thursday including soldiers and civilians in Pakistan's violence-plagued port city of Karachi, police said.

The bomb targeted troops returning to camp by truck after carrying out security duties for by-elections in the city.

"At least 10 people, including soldiers and some civilians were wounded in the bomb blast," senior police official Tahir Naveed told AFP.

Naveed said he could not immediately give further details on the casualties but Imran Shaukat, another senior police official, confirmed the incident and the number of wounded.

An unprecedented wave of killings and kidnappings has hit Karachi, a sprawling metropolis of 18 million people on the Arabian Sea and Pakistan's economic heart.

Bloody gang wars fed by ethnic and political bitterness, drugs and the Taliban, have created a culture of impunity, and the past two years have seen record death tolls.

In the first six months of 2013, 1,726 people were killed in Karachi compared with a previous high of 1,215 in the same period last year, according to the Human Rights Commission of Pakistan.