Pakistan’s military have been engaged in a deadly standoff for more than 24 hours with armed militants who hijacked a train and took hostages, in a dramatic escalation of an insurgency that has plagued the region for decades.

The Baloch Liberation Army (BLA), a militant separatist group active in the restive and mineral-rich southwestern Balochistan province, claimed responsibility for the attack.

Around 450 passengers were on the Jaffer Express enroute from Balochistan’s capital Quetta to Peshawar in the north, when militants opened “intense gunfire” as the train traveled through a tunnel early in its journey, according to officials.

By early Wednesday morning, 155 hostages had been rescued and 27 militants killed, according to the security sources, with video showing elderly women, men and children looking pale, frightened – but relieved – as they reunited with their families. It’s unclear how many people are still being held.

At least 10 civilians and members of Pakistan’s security forces had been killed, according to government and railway officials.

The security sources accused the militants of being in contact with handlers in Afghanistan.

Pakistan’s military and government have long accused Afghanistan of providing sanctuary to militant groups, something its Taliban leaders have denied.

Scores of injured hostages have been taken to hospital for treatment, with an effort to rescue those still kidnapped underway.

An evolving insurgency

Tuesday’s kidnapping is an audacious moment for a separatist insurgency who seeks greater political autonomy and economic development in the strategically important and mineral-rich mountainous region.

But it also highlights the ever-deteriorating security situation there – one that Pakistan’s government has been grappling with for decades.

Balochistan’s population – made up mostly of the ethnic Baloch group – is deeply disenfranchised, impoverished, and has been growing increasingly alienated from the federal government by decades of policies widely seen as discriminatory.

An insurgency there has been ongoing for decades but has gained traction in recent years since the province’s deep-water Gwadar port was leased to China, the jewel in the crown of Beijing’s “Belt and Road” infrastructure push in Pakistan.

The port, often touted as “the next Dubai,” has become a security nightmare with persistent bombings of vehicles carrying Chinese workers, resulting in many deaths.

Some analysts said Tuesday’s attack marked an escalation in the sophistication of attacks by the insurgents.

The “larger point that the Pakistani state is not grasping … is that it’s not business as usual anymore,” said Abdul Basit, a Senior Associate Fellow at the S. Rajaratnam School of International Studies in Singapore.

“The insurgency has evolved both in its strategy and scale,” he added, saying Pakistan’s approach to tackle the Baloch militants’ “seem to have run its course.”

“Instead of revising its counterproductive policies, it is persisting with them, resulting in recurrent security and intelligence failures,” Basit said.

The BLA has been responsible for the deadliest attacks in Pakistan in the past year.

A suicide bombing by the BLA at a train station in Quetta killed more than two dozen people last November. The previous month, it claimed responsibility for an attack on a convoy of Chinese engineers, resulting in two deaths.

In the wake of Tuesday’s attack, Pakistan’s Prime Minister Shehbaz Sharif vowed to “continue to fight against the monster of terrorism until it is completely eradicated from the country.”

In a statement, he said the “terrorists’ targeting of innocent passengers during the peaceful and blessed month of Ramadan is a clear reflection that these terrorists have no connection with the religion of Islam, Pakistan and Balochistan.”

Analysts say such attacks need urgent attention from the federal government.

“(Tuesday’s attack) has gained global attention and it will worry China, which has its investments in the province – more than any other state,” said Basit. “A major reset of existing security paradigm is required in Balochistan.”

The captain of the Solong cargo ship who was arrested after crashing into a US-flagged tanker off the English coast is a Russian national, the vessel’s owner said Wednesday, as maritime experts search for answers.

The Solong careered into the Stena Immaculate while it was at anchor in the North Sea and carrying huge amounts of jet fuel for the US military, setting fire to both vessels and prompting emergency rescue efforts by the British coastguard.

British police have since opened a criminal investigation into the crash and arrested a 59-year-old man on suspicion of gross negligence manslaughter.

The rest of the crew are a mix of Russians and Filipinos, the spokesperson added.

Martyn Boyers, chief executive of the nearby Port of Grimsby East, had expressed disbelief that such a crash could have happened, given the sophistication of modern shipping technology.

The Portuguese-flagged Solong was still burning more than a day on from the crash, while the fire on the Stena Immaculate was put out earlier Tuesday.

A missing crew member from the Solong is presumed dead, according to Britain’s maritime minister Mike Kane, after a search and rescue operation was called off late Monday.

The cargo ship’s other 13 crew members were rescued, along with the full 23-person crew of the Stena Immaculate, Kane said.

The Stena Immaculate, which is managed by the United States logistics firm Crowley, is part of a fleet of 10 tankers involved in a US government program to supply its military with fuel. The Department of Defense’s “Tanker Security Program,” according to Crowley, “ensures a commercial fleet can readily transport liquid fuel supplies in times of need.”