The men -- Faizan Haider and Muhammad Faheem -- shot and killed by US official Raymond Davis in Lahore on January 27 "belonged to the security establishment" and "found the activities of the American official detrimental to our national security", an unnamed security official told The Express Tribune newspaper.
Faheem's widow committed suicide on Monday by consuming pesticide, saying she decided to take her life as she believed her husband's killer would be freed without trial.
The Pakistan government's "tough stance" on the issue was also a "reaction to the attempts by certain elements in Washington to implicate the country's top spy agency, the Inter-Services Intelligence in the November 2008 Mumbai attacks," the official was quoted as saying.
"The government is very angry with the decision of an American court to summon top ISI officials in connections with the Mumbai attacks," the official said. ISI Chief Lt Gen Ahmed Shuja Pasha and Jamaat-ud-Dawah chief Hafiz Mohammed Saeed have been issued notices by the court in Brooklyn after relatives of two Jewish victims of the Mumbai attacks filed a lawsuit last year.
Davis had told investigators that he acted in self-defence after the two armed men tried to rob him. Police officials in Lahore had earlier said evidence gathered by them suggested the dead men were robbers. A case has also been filed for a robbery allegedly committed by the two men shortly before they were killed.
The security official, requesting anonymity, as he was not authorised to speak to the media, said Pakistani President Asif Ali Zardari, Prime Minister Yousuf Raza Gilani and Pakistan Army Chief Gen Ashfaq Parvez Kayani discussed the issue of Davis in a meeting last week.
The three leaders "thought it was advisable to resist the US pressure on the Raymond Davis issue and believed the detained American national should not be released at this stage," the official was quoted as saying.
Officials in the Pakistan foreign office confirmed the government's position on the Davis issue but said he would eventually be released once there is a "firm assurance from the US that such incidents would not recur", the report said.
The government is contemplating to ask the US to waive Davis's immunity and try him in an American court, the officials said. A US embassy official told the daily that the American government had "no plans yet to agree on such a step".
3 Americans barred from leaving Pak
In a related development, the Pakistan government has barred three more US nationals from travelling out of the country following allegations that they were in the vehicle that crushed a man to death in Lahore immediately after Davis shot and killed the two men.
The Punjab government has sought assistance from the federal government in securing the custody of the three American men accused of killing the third Pakistan while they were rushing to help Davis. "We have sought access to get custody of these accused because they are wanted by the Punjab police in connection to the Raymond Davis case," said Pervez Rashid, spokesman for the Punjab Chief Minister Shahbaz Sharif.
"The interior ministry has placed the names of the three Americans, including the driver of the US consulate in Lahore, on the exit control list," an interior ministry official was quoted as saying by The Express Tribune.
The exit control list empowers the government to prevent any person from leaving Pakistan. The interior ministry, through the foreign office, has written to the US consulate, asking for the three Americans to be handed over to Punjab police, the interior ministry official said. He declined to name the three Americans, saying it might compromise the investigation.
The US embassy said it was not aware of these developments. "We have not received any such information on the issue as yet," said Courtney Beale, acting spokesperson for the embassy. Davis is currently in police custody in Lahore and Pakistani leaders have rejected US demands for him to be released on the ground that he enjoys diplomatic immunity.