The mayor of Pakistan's largest and most populous city has vowed to run his office from prison after being arrested on charges of sedition and terrorism.

Waseem Akhtar, of the Muttahida Qaumi Movement (MQM), has been in prison since his arrest in July but was elected Karachi's mayor last week.

A former minister and parliamentarian, Akhtar won the poll by a landslide, bagging 196 of the 294 votes cast by the city's municipal authorities. He was allowed out of the prison and escorted to the oath-taking ceremony on Tuesday.

"We know Karachi is plagued by a number of issues and these problems are our problems," Akhtar said in his oath-taking speech.

"These are all false charges. After taking oath, I have decided to move a bail application in court. And I am sure I will get justice."

He vowed to seek his freedom in court but said if he is denied, he will "solve the public's problems from jail".

Under Pakistani law, politicians can govern while in police custody but it is not yet clear how Akhtar will be able to work as mayor from prison.

He said he would ask the chief minister of Pakistan's Sindh province to allow him to open an office in jail and make "new rules" so that people would be granted access to him.

'No propaganda can kill MQM'

MQM has dominated Karachi's political scenario since the 1990s but a paramilitary crackdown since 2013 - and a more recent one this year - has undermined its power base in the port city that is home to 20 million people.

The party's chief, Altaf Hussain, is living in self-imposed exile in London where he was granted political asylum in 1992.

MQM activists clashed with police and ransacked a private TV station in Karachi last week, leaving at least one man dead and seven injured. The clashes came after Hussain gave a telephone address to supporters in which he castigated the media for its coverage and told protesters "to storm the offices of TV channels".

Security forces arrested MQM officials while demolishing its illegal offices and sealing the head office, accusing them of torture, murder and racketeering.

MQM denies having any links to criminal activities and accuses paramilitary forces of a series of extra-judicial killings of its members.

"Akhtar is Karachi's mayor, he carries a lot of responsibilities. How can he be put in jail?" Barrister Saif Ali Khan, an MQM leader, told Al Jazeera.

"How can they suspect him of fleeing or committing any crime? They [the government and paramilitary forces] are conducting these arrests to satisfy their egos and to crush MQM. This is taking us nowhere. No propaganda can kill MQM.

Hussain's second-in-command, Farooq Sattar, was forced to disown Hussain at a press conference last week and vowed that the party will be run from Karachi without any input from the "London secretariat".

READ MORE: Explainer - Pakistan's main political parties

On Tuesday, Pakistan's Ministry of Interior said that it was seeking legal action against Hussain in London.

A ministry statement said that the government had sent a dossier on Hussain to British authorities, with allegations of inciting violence and disturbing the law-and-order situation in Pakistan.

"I think they [MQM] will have to work really hard to dissociate themselves from the criminal elements," Sharmila Farooqi, Pakistan People's Party's member of Sindh provincial assembly, told Al Jazeera.

"It will take some time for them to get back on track and to clean their image. If the party wants to survive, it has to focus on internal cleansing."

Analysis - Hamza Ameer, political analyst

MQM has been on damage control by detaching itself from the London secretariat and endorsing itself as a Pakistan-based political party.

Its leadership in Pakistan is also shrinking as a lot of MQM members, including sitting members in the provincial and federal assemblies, have parted ways and joined rival political parties.

But the major setback to MQM has been the arrests of its party workers on terror charges and closure of many of its offices across Karachi and Hyderabad.

Despite that, MQM still has a lot of backing and a lot of people are still ready to vote for it, with or without Hussain. This is because the party has provided them basic facilities and financial support.

This remains the only hope for Sattar and whatever is left of the who continue their efforts of bringing MQM back on track in the political race.