Pecker is a key witness in the case against the former US president, who is accused of falsifying business records to cover up hush-money payment
South Africans and Egyptians were among those injured when an explosive device went off, hitting the bus in Giza, according to the sources.
Images circulating online showed some of the bus' windows shattered.
Sunday's incident comes after three Vietnamese holidaymakers and their Egyptian guide were killed when a roadside bomb hit their bus as it travelled near the pyramids outside Cairo in December.
Egypt's tourism sector has suffered for years due to a series of deadly attacks targeting holidaymakers following the turmoil of the 2011 uprising that toppled longtime ruler Hosni Mubarak.
Authorities have gone to great lengths to lure tourists back, touting a series of archaeological finds and a new museum next to the pyramids, as well as enhanced security at airports and around ancient sites.
The industry has slowly picked up, with tourist arrivals reaching 8.3 million in 2017, compared with 5.3 million the previous year, official statistics showed.
But that figure was still far short of the record influx of 2010 when more than 14 million visitors flocked to see the country's sites.
Pecker is a key witness in the case against the former US president, who is accused of falsifying business records to cover up hush-money payment
The oil and gas conglomerate and Fifa, the world governing body, sign major sponsorship agreement
Toomaj Salehi risks being hanged after the conviction on the Shariah charge of "corruption on Earth" by a Revolutionary Court
Aid groups warn any invasion would add to already-catastrophic conditions for Gaza's 2.4 million people
The American they will face Australia and Serbia on July 15 and July 17 as part of their preparation for the Paris Olympic Games
The leaders emphasise that the deal to release the hostages would bring an immediate and prolonged ceasefire in Gaza
Dubai-based Sumit Augustine has had a philosophical approach towards spending
The regional upswing also defies oil production cutbacks