A Pakistani policeman extinguishes a burning autorickshaw torched by an angry mob following a raid by paramilitary Rangers on the offices of the Muttahida Qaumi Movement in Karachi on Wednesday. 

AFP/Karachi

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

The raid on the Muttahida Qaumi Movement (MQM) headquarters, known as "Nine-Zero", 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.

‘Criminals’ held

"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."

A Rangers statement said those held included one man sentenced to death for the murder of a television news journalist in 2011.

The statement said a "huge quantity of weapons and ammo" were seized in the raid.

"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.

"It was all licensed weapons issued to the MPs of the party," senior MQM leader Haider Abbas Rizvi said.

He said it was a disgrace that a leading political party was "being ridiculed in such a ruthless way".

MQM, whose leader Altaf Hussain lives in exile in London, holds 23 seats in the National Assembly, almost all in Karachi.

The Rangers said there was no resistance during the raid, but television footage showed Rangers soldiers firing gunshots while leaving the offices.

Party worker killed  

Senior police officer Tahir Noorani said that Waqas Ali Shah, an MQM activist, was shot dead.

Petrol stations, schools and colleges were closed and public transport vanished from the roads during the protests by enraged MQM supporters.

Hussain, addressing party workers by phone over a loudspeaker, condemned Shah's killing.

"He was a bright young man, why they shot that innocent boy, what was his sin?" Hussain said.

"The language which was used, and the discriminatory treatment meted out on us, is highly deplorable."

But he also issued a reprimand for harbouring criminals at party HQ.

"You should have handed the criminals, if there were any, over to the law enforcement agencies - why did you put innocent workers' life in danger?" he said.

The Rangers also rounded up Aamir Khan, a senior MQM leader, who was present at the time of the raid.

"We have taken Aamir Khan into custody to enquire about the presence of the criminals with him," the colonel said.