A suicide bomber smashed a truck packed with explosives into housing for a paramilitary force protecting Pakistan's largest city, killing at least one person in the explosion Thursday, Nov 8 morning that sent a large plume of smoke into the sky, officials said, according to The Associated Press.

The blast underlined deteriorating security in Karachi, the sprawling port city of 18 million people that is considered the economic heart of Pakistan. Violence has escalated in recent years in the city as armed groups fight for control of land and resources, and militant groups like the Taliban have used the chaos to consolidate their foothold.

One dead body had been brought to the Abbasi Shaheed Hospital from the early morning explosion, Dr. Saleem Memon said.

A truck driven by a suspected suicide bomber smashed into the gates of a residential apartment block where members of the Rangers security forces live, said Javed Odho, deputy inspector general of the Karachi police.

The Rangers are a paramilitary force that is tasked with helping Karachi police maintain security.

A spokesman for the Rangers, speaking on condition of anonymity in line with regulations, said at least 21 Rangers personnel were wounded in the explosion. He said the blast would not deter the Rangers from pursuing operations against militants in the city.

Witnesses reported seeing a large plume of smoke in the sky. Pakistani television images of the blast sight showed what appeared to be an apartment block with a gaping hole in the middle where the bomb went off and part of the two-story building was razed.

There was no immediate claim of responsibility. Taliban militants are known to operate inside the city and have targeted security officials and buildings in the past.