Karachi is in the grip of a long-running wave of political and sectarian violence and objections have been raised over voter lists ahead of a general election due in May next year.

"It is clear that the electoral rolls of the city of Karachi are required to be revised by the Election Commission," judge Azmat Saeed said in a judgement of the bench headed by chief justice Iftikhar Muhammad Chaudhry.

"In view of the peculiar security situation in Karachi... such verification must be carried out by the Election Commission with the help and assistance of Pakistan Army and the Frontier Corps," Saeed said.

The judge said Karachi's voter lists "do not inspire confidence" and warned that the possibility a significant number of residents may have been "disenfranchised" could not be ignored.

The Election Commission has also admitted that door-to-door verification of electoral roles has not been carried out, Saeed said.

He said the petitioners had pointed out "gross errors and irregularities" in the preparation of the electoral rolls and they alleged that approximately half of the city's six million voters had had their registration moved to other parts of the country.

The judge said the petitioners complained that names of "unverified" voters had been added to the rolls, "which is likely to lead to rigging in the forthcoming.

Copyright AFP (Agence France-Presse), 2012