South Africa's decision to pull out of their tour of Pakistan at the eleventh hour left cricket officials here utterly shocked.

The Proteas were scheduled to arrive in Pakistan tomorrow to play three Tests and as many one-day internationals at different venues across the country including Karachi where a bomb went off in a city office block on Friday.

Police ruled out terrorism, linking the blast instead to a commercial dispute involving the 12-storey Kawish Crown Plaza at Sharea Faisal area.

It was the second blast in the same office in two months. The July 11 bomb, also described as low-intensity, exploded outside office hours but killed two people.

Pakistan Cricket Board (PCB) chief executive Rameez Raja derided the incident as "uncalled for and disappointing".

"They have shocked us by calling off the tour," Raja was quoted as saying.

South Africa had only given the green light to the tour on Thursday, after dispatching its own security delegation to Pakistan to assess venues considered risky in commercial capital Karachi and the northwest border city Peshawar.

They were also scheduled to play a Shoaib Muhammad benefit match at the Karachi Stadium on September 24.

The United Cricket Board (UCB) of South Africa had early this month asked PCB to shift matches from Karachi and Peshawar.

"We are utterly disappointed that South Africa has cancelled the tour. It's a big, big blow to Pakistan cricket as we were in a rebuilding process," said PCB spokesman and general manager (media) Samiul Hassan yesterday.

Talking to this correspondent, Samiul also expressed that it was very clear to them why South Africa had cancelled the whole trip for a bomb blast in Karachi only without considering the other factors.

"They initially wanted to shift venues from Karachi and Peshawar.

But now they have cancelled the whole trip. It's really unfortunate for cricket," lamented said.

He added that International Cricket Council (ICC) held a meeting in Mumbai, India, quite successfully despite a huge bomb blast and the chief executive of UCB was also present there without any fear.

"Again, New Zealand have not cancelled their tour of India despite that bomb blast that killed so many people. Even the Kiwis are still set to play a match in Mumbai," Samiul said adding that Pakistan were eagerly waiting for this tour.

Samiul, however, added that PCB would still try to convince the South African officials to make the tour.

It may be mentioned that New Zealand abandoned their tour of Pakistan after a bomb blast outside their hotel last year.

After that Pakistan had to play their home series against West Indies and Australia at neutral venues as they declined to tour Pakistan.

Bangladesh have led the return of foreign cricket to the terror-hit Islamic republic, launching a three-Test series and five one-day matches last month. Their Test matches in Karachi and Peshawar passed without any security incidents.

They will play their last match at the Karachi National Stadium today.