Sri Lanka has become the latest touring team to express reservations about playing at some venues in Pakistan because of security concerns.
The Asian champions are due to tour Pakistan in October to first play in a triangular series, also involving Zimbabwe, before two Tests against the hosts.
"Sri Lanka has conveyed its reservations about playing at some venues. They have indicated they would not be comfortable playing at them because of some security concerns," Pakistan Cricket Board chairman Shaharyar Khan told Reuters on Wednesday from London.
"Because of the Sri Lankan concern we are having a second look at the venues to host the Tests," he added.
The Pakistan Board is yet to announce the venues for the Tests but they have scheduled one match of the one-day series in the port city of Karachi.
Australia, South Africa and New Zealand all refused to play at Karachi in the last two years while earlier this year India rejected a Test match at Karachi and finally settled for a One-Day International after much persuasion by the Pakistan Board.
Karachi has been the target of attacks and suicide bombings over the past two years but when India played in March the match went off smoothly in front of a packed stadium.
Sources at the Board confirmed that the PCB had initially scheduled a Test against Sri Lanka in Karachi but are now looking at other options.
"We are making arrangements to provide the same security cover to Sri Lanka and Zimbabwe that we have done for the South Africans, New Zealanders and Indians since last year," Khan said.
The New Zealand team flew home in May 2002 without playing a scheduled Test in Karachi after a suicide bombing outside their team hotel on the first day of the match killed 14 people.
