Pakistani security forces raided the offices of the main political party in Karachi on Wednesday, arresting activists and seizing a "huge quantity" of weapons.

Pakistani security forces raided the offices of the main political party in Karachi on Wednesday, arresting activists and seizing a "huge quantity" of weapons.

The raid on the Muttahida Qaumi Movement (MQM) headquarters, known as "90", sparked an angry response from the party, with workers shutting down large parts of Pakistan's biggest city.

At least one supporter of the MQM, the fourth largest party in parliament, died as government paramilitary Rangers opened fire on protesting activists.

Rangers personnel raided the offices in central Karachi acting on an intelligence tip-off that convicted criminals were hiding inside.

"We have arrested five to six people who had criminal backgrounds," Colonel Tahir Mahmood, who was leading the team, told reporters outside MQM headquarters.

"There were some criminals to whom the court has handed down the death
sentence."

"The finding of weapons carries a question mark and we will investigate it," Mahmood said.

MQM condemned the raid and insisted that the weapons were all legally held.

The MQM presents itself as a voice of political moderation and secularism, though critics accuse it of operating as a violent mafia-like organization.