Pakistani police have detained a number of people for questioning in connection with the kidnapping of an American development expert in the eastern city of Lahore, investigators said on Sunday.
In a pre-dawn raid on Saturday, six to eight assailants broke into the house of the man, identified by the U.S. State Department as Warren Weinstein, and abducted him after overpowering security guards.
Shahzada Saleem Butt, the Deputy Superintendant of the Punjab Police, told NBC News that "no arrests have been made, but a guard and a driver are under suspicion and being questioned."
No one has claimed responsibility for the abduction, he added.
U.S. embassy spokesman Alberto Rodriguez said they had not yet been informed about any progress in the case. "Police are investigating. We are waiting."
Kidnapping for ransom is relatively common in Pakistan, although foreigners are not often targets. Militants also occasionally take foreigners hostage but these incidents have taken place in the volatile western regions bordering Afghanistan, where Islamist insurgents are very active.
Weinstein has been identified as working for J.E. Austin & Associates, an Arlington, Virginia-based consulting firm, on a development project in lawless tribal areas where Pakistani troops have been battling Islamist insurgents for years.
Police said the gunmen barged into house on the pretext of sharing a meal with the guards, a common practice during the Muslim fasting month of Ramadan, which started early this month. The attackers then forced Weinstein's driver to knock on his bedroom door. When he opened it, they took him.
The victim, in his 60s, had been living in Pakistan for five to six years, according to police. He mostly lived in Islamabad but had been traveling to Lahore.
A staff member of J. E. Austin Associates in Lahore who did not want to be identified told NBC News that staff had planned a farewell party for Weinstein Sunday since he had been scheduled to leave for the United States on Monday.
"He (Weinstein) is a nice man. I appeal to his abductors to release him. I pray that no harm comes to him," the staffer said.
Relations between Pakistan and the United States have sharply deteriorated since January, when a CIA contractor killed two Pakistanis in Lahore, and worsened after U.S. Navy SEALS killed al-Qaida chief Osama bin Laden in a raid in northwestern Pakistan that Islamabad termed a breach of its sovereignty.
Pakistani Taliban, linked to al-Qaida, have claimed responsibility for kidnapping a Swiss couple in July in the volatile southwestern province of Baluchistan.
Eight Pakistani employees of a U.S.-based aid organization, American Refugee Committee (ARC), were kidnapped in Baluchistan last month.