Two suicide bombers struck near the heart of the Pakistani military on Tuesday, killing 25 people and wounding 70, many of them Defence Ministry staff on their way to work in the city of Rawalpindi.

There was no claim of responsibility but the Interior Ministry said evidence pointed to al Qaeda-linked militants who are battling security forces near the Afghan border.

One bomb blew up a bus carrying Defence Ministry staff about a kilometre from army headquarters, said military spokesman Major-General Waheed Arshad. The second went off in a market area of Rawalpindi, the sister city of Islamabad where Musharraf and many other top military officials live and where Islamabad’s international airport is located.

“Both were suicide bombings but I have no details about how they were carried out,” Arshad said. Some officials said the staff on the bus were from an agency involved in atomic work, while others said they were from a security agency.

Interior Ministry spokesman Javed Iqbal Cheema said the bus belonged to the Defence Ministry and was carrying employees of various government departments. He denied reports that it was carrying intelligence agency staff.

The body and roof of the bus were almost totally blown away. Pieces of flesh and strips of clothing hung limply from the twisted metal frame as rescuers struggled to pull out the dead.

Deputy Information Minister Tariq Azim Khan said a suicide bomber had apparently managed to board the bus that was blown up.

Police said the second blast, also close to army headquarters, was caused by a bomb on a motorcycle.