ISLAMABAD, Pakistan (CNN) -- Gunmen opened fire on a military vehicle in Islamabad on Thursday, killing an army brigadier and a soldier, officials said.
It was the second time in three days that militants had launched an attack in the capital.
Gunmen on two motorcycles opened fire on the vehicle carrying the brigadier and the soldier Thursday morning, a military official said. The driver of the vehicle also was wounded.
An official from the United Nations confirmed a Pakistani news report, that the assassinated brigadier, Moinuddin Ahmed, was the commander of the Pakistani peacekeeping contingent in Sudan, at home on leave.
"He was on R&R (rest and relaxation) here at home," said Manuel Bessler, head of the U.N.'s Office for the Coordination of Humanitarian Affairs in Islamabad. "And the poor guy, on his last day, because tomorrow he was supposed to go back to his duty post, they killed him."
The attack follows twin suicide bombings at an Islamic university Tuesday.
At least six people were killed and 29 others wounded when suicide bombers detonated explosives in the men's and women's sections of International Islamic University.
In recent weeks, Pakistan has been relentlessly rocked by suicide attacks as Islamic militants have retaliated against a military offensive to rout insurgents operating along the Pakistan-Afghan border.