The family of a Palestinian Authority (PA) professor and Hamas member accused Israel's Mossad spy agency of assassinating him on the streets of Kuala Lumpur on Saturday.
Malaysian authorities said Fadi Mohammad al-Batsh, 35, was killed by two suspects believed to have ties with a foreign intelligence agency in a drive-by shooting on his way to dawn Muslim prayers.
Home Minister Ahmad Zahid Hamidi, quoted by the state-run Bernama news agency, said Batsh was "an electrical engineer and an expert at making rockets."
Ahmad Zahid, who is in charge of Malaysia's security, said al-Batsh was scheduled to leave for Turkey on Saturday, adding that Malaysian police would request the help of Interpol to track down the suspects, believed to be European nationals.
Meanwhile, a Hamas statement accused Israel's Mossad of being behind the assassination, and said al-Batsh was one of its members, mourning him as a "martyr."
Kuala Lumpur police chief Datuk Seri Mazlan Lazim said one of the two suspects on a high-powered motorcycle "fired 10 shots, four of which hit" al-Batsh. "He died on the spot."
"The police also found two empty bullet shells there," the police chief said, according to Bernama.
He said that footage from closed-circuit television cameras near the scene of the shooting showed that the assailants waited for around 20 minutes in the area before attacking.
"We believe the lecturer was their target because two other individuals walked by the place earlier unharmed. We will view the recordings of all the CCTV in the area," he said.
A PA representative in Malaysia told AFP that Batsh had lived in Malaysia for the past 10 years. However, he refused to comment on the idea that the Mossad might be responsible, saying, "We have to wait for the official investigation."
The Mossad has been accused of assassinating several terrorists and terror masterminds in the past, but has never confirmed such activities.