Security officials inspect the site after the explosion of a bomb, in Karachi. AFP

One person was killed and 12 injured in a bomb blast late on Thursday in Karachi, police said, just two weeks after a suicide attack by a Pakistan separatist group killed four in the same city.

The explosion tore through the Saddar neighbourhood of Pakistan's most populous city at around 11:00 pm (1800 GMT).
"Initial investigation suggested that the explosive material was planted in a motorcycle that was parked near a trash bin," said local police station house officer Sajjad Khan.The target of the attack was not immediately announced.

However Khan said a coast guard vehicle was among "several" damaged in the blast while the one person slain was a "passerby".
Last month a female suicide bomber killed four people, including three Chinese nationals, in an attack on a minibus carrying staff from a Beijing cultural programme at Karachi University.

The Baloch Liberation Army (BLA) -- a group fighting for independence in Pakistan's largest and most impoverished province -- claimed responsibility for the April 26 strike.

China has made massive energy and infrastructure investments in Balochistan under a $54 billion scheme known as the China-Pakistan Economic Corridor.

Agence France-Presse