Dhaka, Bangladesh (CNN) -- Gunmen shot and killed a Saudi diplomat in Dhaka, Bangladesh's capital, on Tuesday, police said.
Bangladesh police said Khalaf Al Ali, 45, had served two years at the Royal Embassy of Saudi Arabia in Dhaka as head of citizens' affairs.
The Saudi Embassy in Dhaka confirmed the death but declined to make a comment.
Ali was shot dead in the city's highly secured Gulshan diplomatic zone in front of his rented apartment at about 1 a.m. Tuesday, and he died at a local hospital about 5 p.m., authorities said.
Lutful Kabir, a deputy commissioner of Dhaka's metropolitan police, said no motive for the killing has been found.
"He was shot in the left chest from a close distance," he said after an initial investigation.
"We're shocked. ... It's unexpected and unfortunate. ... We'll use all possible means to bring the culprits to book," Bangladeshi Foreign Minister Dipu Moni said.
"Bangladesh and Saudi Arabia maintain very good relations, and I believe it will not affect the relations," she said.
Police said Ali lived alone at his Gulshan apartment and went for a walk late every night. Tapos Rema, a guard at the Saudi official's home, said Ali went for the walk as usual and was attacked when he returned.
Witnesses said that when Ali was near his home, shots were fired from a car that then fled.
Shamsul Islam, a junior Bangladeshi minister for home affairs, said "the matter is being investigated, and we'll bring the perpetrators to justice as soon as possible."
Saudi Arabia, where more than 2 million Bangladeshis stay and work, is a key ally and a major donor to Bangladesh.
In recent years, Riyadh has tightened recruitment from Bangladesh.
In October, Saudi authorities executed eight Bangladeshi workers in public for their alleged involvement in an armed robbery in which an Egyptian security guard was killed. Dhaka criticized the beheadings, as did the United Nations.