Twin suicide car bomb attacks killed 15 people in the Pakistani garrison town of Rawalpindi today on the eve of the return of former prime minister Nawaz Sharif from exile in Saudi Arabia.
The two blasts heightened fears of insecurity as Pakistan heads towards a general election in early January amid political convulsions under emergency rule. No one has claimed responsibility for the attacks in which the bombers died.
One car rammed a ministry of defence bus taking personnel to work at an intelligence service office, while another bomber blew up his car at a checkpoint outside army headquarters.
In late October a suicide attacker killed seven people near President Pervez Musharraf's army residence in Rawalpindi, which is next door to the capital.
Politically isolated, Gen Musharraf allowed another former prime minister, Benazir Bhutto, to return to Pakistan last month after years abroad, by granting her protection against prosecution in old corruption cases she says were politically motivated.
Gen Musharraf had looked on Ms Bhutto as a potential ally, but she became confrontational once she got back. Her distrust of the establishment was reinforced by a suicide attack on her homecoming parade that killed at least 139 people a month ago.
Islamist militants have waged a suicide bomb campaign since the army stormed the Red Mosque in the capital, Islamabad, to crush an armed radical movement.
Today's attack on the bus killed 15 people on board, while two soldiers were critically wounded by a car bomber who detonated explosives when they stopped him less than 100 metres from the main gates to the army's general headquarters.
"Both were suicide attacks," army spokesman Major-General Waheed Arshad said. "There were 50 people sitting in the bus. Many are injured, many are okay," he said.
Two security officials told Reuters on condition of anonymity that more than 35 people were killed, but there was no independent verification of the number of casualties.
After Saturday's attack, police cordoned off the area and put up tents to obscure the view, but a Reuters witness saw the burnt-out bus just inside the gate of the intelligence service compound.
"We could not see any bodies as the bus was all in flames. The wreckage of the bus and the car was all over the place," said Wazir Gul Abbasi, owner of a three-storey hotel just opposite the intelligence office, saying there was a huge explosion.
Pakistan is still under emergency rule imposed by Gen Musharraf three weeks ago in an apparent bid to safeguard his presidency from challenges to his re-election.
A purged supreme court has since dismissed those challenges and Gen Musharraf is expected to be sworn in for a second five-year term, this time as a civilian, next week.
Mr Sharif, the prime minister deposed by Musharraf in a 1999 coup, plans to return to Pakistan from Saudi Arabian exile on Sunday, his brother Shahbaz Sharif told a Pakistani news channel.
Gen Musharraf, under intense criticism at home and abroad for imposing emergency rule three weeks ago, agreed to Sharif's return in discussions with Saudi King Abdullah in Riyadh this week, according to a leader of the ruling Pakistan Muslim League.