The International Cricket Council (ICC) will not be sending match officials to Pakistan for the tour of Zimbabwe should the limited overs series go ahead, the governing body said on Sunday.
The ICC said a security consultant had advised against sending officials to Pakistan, who will instead use their own umpires for the matches if Zimbabwe decide to tour the trouble-torn nation.
The appointment of local match officials will not affect the official status of the games, the ICC said in a statement.
"The ICC today advised the Pakistan Cricket Board (PCB) and Zimbabwe Cricket (ZC) that it will not be appointing its match officials for the upcoming series between Pakistan and Zimbabwe," the statement read.
"The ICC Board, during its April meeting, had decided that the playing conditions relating to the appointment of match officials could be waived to allow the PCB to appoint local match officials for this series should the ICC decide not to send its umpires and referee due to the current security situation in Pakistan.
"If this was to occur, the matches would still be considered 'official cricket', even though they will not be played strictly in accordance with the ICC standard playing conditions."
Although the PCB claimed on Friday they had received an assurance from ZC that the tour was on, Zimbabwe continue to say only that discussions are ongoing.
Zimbabwe coach Dav Whatmore, who coached Pakistan in the past, took to Twitter on Sunday to suggest the team would travel.
"Looking fwd to returning to Pakistan as opposition coach and reacquainting with friends. Team zim are & will be working hard for a win!" he said from his official account.
A ZC delegation which visited Lahore, the venue for all matches on the tour, approved security measures put in place by local authorities last week.
But the terror attack on a bus in Karachi that killed at least 45 people this week led Zimbabwe's supreme sports regulatory authority, the Sports and Recreation Commission, to advise that the tour be cancelled.
Zimbabwe were due to be the first test-playing nation to tour Pakistan since a 2009 attack on Sri Lanka's team bus in Lahore left six Pakistani policemen and a van driver dead. Some players and a local umpire were injured.
Zimbabwe are scheduled to play two Twenty20 internationals, starting on May 22, and a three-match one-day series.
