Ousted Pakistani prime minister Nawaz Sharif gestures as he boards a Lahore-bound flight at Abu Dhabi International Airport on July 13. (Drazen Gorgic/Reuters)

Former Pakistani prime minister Nawaz Sharif flew home to start a 10-year prison sentence Friday, hours after a bombing at an election rally killed at least 132 people, heightening security concerns for the country’s already fraught national elections.

Sharif, who was found guilty of corruption this month, arrived in Lahore on Friday evening after he and his daughter Maryam Nawaz — who was sentenced to seven years in the same case — boarded a plane in London. The pair was taken into custody shortly after their arrival at the Lahore airport.

His return is seen as a public show of acquiescence meant to win sympathy from voters in an election that analysts predict could either spell the downfall of one of Pakistan’s most charismatic leaders or lead to years of civil unrest and political instability.

That fragility was underscored earlier in the day in the southwestern province of Baluchistan when one of the deadliest bombing attacks in Pakistan’s recent history ripped through a gathering in support of Nawabzada Siraj Raisani, who was running for a provincial legislature seat in the Mastung district.

Raisani, whose recently formed Baluchistan Awami Party is viewed as pro-military and against separatist groups operating in that part of Pakistan, which borders Afghanistan, was with other party workers when a suicide bomber blew himself up in the middle of the crowd. Raisani was among those killed.

A man who was injured in a suicide attack that targeted an election rally of the Baluchistan Awami Party talks on a mobile phone in Mastung, Pakistan. (Epa-Efe/Rex/Shutterstock)

The Islamic State asserted responsibility for the attack, which also injured more than 500 people, prompting fears of more terrorist activity in the country after several years of relative calm.

“These devastating terrorist attacks are a serious threat, and it seems terrorists want to sabotage the polls, to challenge the writ of state and to create anarchy,” said Amir Rana, a security analyst based in Islamabad. “I don’t see any chance of the elections getting derailed, but still an atmosphere of fear has been created, which is not good for elections.”

The blast marked the second deadly bombing in less than a week. About 20 election workers with the secular Awami National Party were killed Tuesday in a suicide blast in the northwestern city of Peshawar.

Into that climate arrived Sharif, seeking to further heighten emotions over the country’s direction in what was meant as a public indictment of Pakistan’s military and the conservative agenda of his chief political opponent, former cricket star Imran Khan.   

After boarding the flight Friday, Sharif posted a video on social media urging supporters to show up in droves for the July 25 election and thereby resist what he has called a conspiracy to oust his ruling party from power.

His Pakistan Muslim League-N faces a stiff challenge from Khan’s Pakistan Justice Movement for control of the National Assembly, with many analysts calling the race a toss-up that could lead to a fractious coalition government.

“I know that I have been given 10 years’ imprisonment, and I will be taken straight to the prison, but I want to tell the Pakistani nation that I am doing this for you,” Sharif said in his video. “I am giving this sacrifice for your future, so give me your full support and go with me with your hands in my hands.”

Maryam Nawaz tweeted a photo of her hugging her distraught daughter and son before leaving for her flight, with the caption: “Goodbyes are hard, even for the grown-ups.”

In turn, Khan tried to blame Sharif for the violence in Baluchistan.

“Beginning to wonder why whenever Nawaz Sharif is in trouble, there is increasing tension along Pakistan’s borders and a rise in terrorist acts?” he posted on Twitter. “Is it a mere coincidence?

The political drama has threatened to wipe away a relative sense of calm in Pakistan that has lasted for several years.

It began when Sharif was ousted from power last July in a case that grew from the 2016 Panama Papers leaks, which revealed some of the family’s financial dealings.

That led the National Accountability Bureau to charge Sharif and his daughter with hiding the family’s wealth through the ownership of London apartments and other foreign properties.

When the two were sentenced last week, supporters of one of the country’s two premier political dynasties in recent decades took to the streets in rallies that accused the national army of manipulating the indictments and that called Khan a puppet of the military.

While Sharif’s plane was in the air Friday, more such clashes broke out in Lahore, as part of a rally that Sharif’s brother, ­Shahbaz Sharif, the current president of the Pakistan Muslim League-N, tried to organize.

The protesters accused police of quashing the demonstration by blocking the roads leading to Lahore, which authorities denied doing. Some supporters scuffled with the police at rallying points.

In hopes of preventing more violence, the army announced earlier this week that it would station 370,000 troops inside voting areas around the country, a move that is also meant to preempt allegations of vote-rigging, which Khan’s supporters used to cast a shadow over the legitimacy of the national government in 2013.

Michael Kugelman, a senior associate for South Asia at the Wilson Center in Washington, said some political observers initially dismissed the army’s plans for 370,000 troops as over the top.

But if the Islamic State is becoming more active in Pakistan, “it’s a bit harder to make
an overkill argument now,” Kugelman said. “Though the terrorism threat in Pakistan has receded in recent years, the danger is still clear and present. And that’s an unsettling reality just days before a major election.”

Olivo reported from Kabul. Haq Nawaz Khan in Peshawar contributed to this report.