(Updates casualties, adds background, paragraphs 2-6)
By Syed Raza Hassan
ISLAMABAD, Jan 20 (Reuters) - A suicide bomber killed four people in a crowded market on Monday near the Pakistani army headquarters in the city of Rawalpindi, not far from the capital Islamabad, police said.
The market, 10 minutes' walk from the army headquarters, is in one of the most secure areas of the city, said Rawalpindi police chief Akhtar Hayat Lalika. The area was cordoned off by the military immediately after the blast.
About a dozen people were wounded, Lalika said.
The attack comes a day after a Taliban bombing killed 20 Pakistani soldiers near the largely lawless, tribal region of North Waziristan.
Sunday's attack prompted Prime Minister Nawaz Sharif to cancel his trip to the World Economic Forum in the Swiss resort of Davos.
His government is keen to pursue peace talks with the Pakistani Taliban to end the insurgency but there has been an upsurge in attacks since Sharif won elections in May 2013. (Reporting by Syed Raza Hassan; Writing by Katharine Houreld; Editing by Paul Tait)