KUALA LUMPUR (NYTIMES) - Fadi al-Batsh, a well-liked electrical engineering lecturer and devout family man, always had a smile for his friends and students in the seven years since he moved to Malaysia from his native Gaza.

On Saturday (April 21), as he walked outside his apartment building in suburban Kuala Lumpur, he was gunned down in a hail of at least 14 bullets by two men on a motorcycle.

It was the Palestinian man's undercover job - as what intelligence officials described as a technology expert for the military wing of the Gaza-based Hamas movement - that had put him in the cross hairs.

Malaysian officials said the attackers were "most likely born in the Middle East or in the West" but would not directly say who they thought was behind the killing. Batsh's family blamed Mossad, the Israeli spy agency.

That claim has been confirmed by Middle Eastern intelligence officials, who said the killing was part of a broader operation ordered by the Mossad chief, Yossi Cohen, to dismantle a Hamas project that sends Gaza's most promising scientists and engineers overseas to gather know-how and weaponry to fight Israel.

Batsh, who in 2013 co-wrote a paper on drone applications, had been sent to Malaysia to research and acquire weapon systems and drones for Hamas, the intelligence officials said, speaking on condition of anonymity to discuss a classified program.

Mossad has been particularly interested in Hamas' advances in unmanned aerial and underwater vehicles, the officials said, which could be used to attack Israeli targets more effectively than the rockets Hamas used during its last war with Israel.

Israel has distanced itself from allegations that it was responsible for Batsh's death. Defense Minister Avigdor Lieberman blamed the assassination on internal rivalries within the Palestinian leadership.

THE MALAYSIAN CONNECTION

The killing of Batsh, 34, in the Kuala Lumpur suburb of Gombak, known locally as Little Arabia, is bringing to light not only the increasing presence of Hamas and other groups here but also Malaysia's emergence as an epicentre of international intrigue.

This was the second high-profile assassination in the Malaysian capital in little more than a year. In February 2017, Kim Jong Nam, the half brother of the North Korean leader, Kim Jong Un, was killed at Kuala Lumpur International Airport by two women who prosecutors said smeared a nerve agent on his face. The women, from Indonesia and Vietnam, are on trial for his death, but at least seven North Koreans suspected of being linked to the killing escaped or were allowed to leave the country, officials said.

Malaysia is also known as a port for contraband, ranging from North Korean weapons to endangered animal products and illegally felled trees.

Malaysia's government has for decades been sympathetic to the Palestinian cause: It has no diplomatic relations with Israel, and Prime Minister Najib Razak visited Gaza in 2013 at the invitation of Hamas, which governs the territory. The intelligence officials said that Hamas, in recent years, had begun seeing the country as an ideal place to incubate its research ambitions.

In another case, in 2010, Palestinians who had been sent to Malaysia trained in paragliding as a potential tool for attacks, according to a statement from the Israeli secret service. Malaysian officials denied any involvement in such a plot.

A KIND PROFESSOR

Colleagues and students of Batsh in Malaysia, where he lived with his wife, Enaas al-Batsh, and their three young children, characterised him as a kind professor who was dedicated to improving life in his native Gaza. His public research focused on renewable energy, and he spoke about wanting to bring abundant electricity to a Palestinian territory always short of power.

Batsh won scholarships from a Malaysian sovereign wealth fund, making him the first Arab to earn such an honour. In 2016, Mr Najib, the Malaysian prime minister, presented Batsh with an award.

"I don't know about his politics back at home, but I know that he was a very big inspiration for all of us for making it out of Gaza and succeeding in Malaysia," said Mr Jailani Othman al-Kathery, a Yemeni English teacher who attended a mosque in Gombak where al-Batsh taught Quran classes and served as an imam.

Batsh told friends in Malaysia that he had narrowly avoided an attempt on his life while still living in Gaza. In 2014, his uncle, the Gaza police chief Tayseer al-Batsh was nearly killed by Israeli airstrikes. Eighteen members of the Batsh family died in those raids.

But Batsh did not dwell on his family's tragedy, his friends in Malaysia said, although he wrote social media posts criticising Israel over the conflict with Gaza.

"Most everyone in Gaza has lost a member of the family," said Hafidzi Mohammed Noor, chairman of Humanitarian Care Malaysia, a charity that provides humanitarian assistance to Gaza. "For him, for all the Palestinians here in Malaysia, this is normal."

Over the weekend, a mourning tent was set up in the Jabaliya refugee camp in Gaza, where Batsh grew up. Ten masked members of the Qassam Brigades, Hamas' armed wing, were stationed in front of the tent, a positioning that usually denotes the death of a top fighter.

Banners hung in the tent described Batsh as an "engineer commander" for the Qassam Brigades and "our martyr to God." Another relative of Batsh's was said by family members to be a commander in Islamic Jihad, a separate militant group that operates in Gaza.

On the day he was killed, Batsh was supposed to travel to Istanbul to attend an academic conference. One Middle Eastern intelligence official, however, said that Hamas' efforts to cultivate its scientists living abroad were directed from Istanbul and that Batsh was scheduled to meet with the head of the unit, Maher Salah, upon arrival in Turkey.

Western and Middle Eastern intelligence officials said that Batsh may have been involved in negotiating North Korean arms deals through Malaysia. Egypt recently seized a shipment of North Korean communications components used for guided munitions destined for Gaza, they said. One intelligence official said that Batsh had helped mediate the deal.

Although such weapons are under international sanctions, the United Nations said in a report last year that a shell company run by North Korea's intelligence agency had been hawking military-grade communications systems from Malaysia.

Malaysian officials rejected that report. And this week, officials here would not comment on the claims that al-Batsh had been researching or trying to buy weapons systems.

HAMAS ABROAD

Batsh is not the first Hamas-linked engineer to be targeted abroad.

In 2011, a Palestinian electrical engineer named Dirar Abu Sisi was abducted in Ukraine and ended up in an Israeli jail more than a week later. He was sentenced to 21 years in prison for aiding Hamas in its manufacture of missiles, among other convictions.

In 2016, Mohammed Zawahri, a Tunisian scientist and Hamas military commander who was said to be developing drone warfare technology, was shot dead in the Tunisian city of Sfax. In January, a car bomb injured Mohammed Hamdan, a Hamas operative who was said to be building a workshop to produce missile parts and drones in Sidon, Lebanon.

On Wednesday, the Malaysian police said that the motorcycle used in al-Batsh's murder had not been stolen. They released a photograph of one of the suspects, a pale-skinned man with a beard, and said he was probably still in the country.

Batsh's body was released by the Malaysian authorities on Wednesday, and a funeral was held at the Gombak mosque where he served as an imam.

At a news conference Tuesday, his widow said she would return to Gaza with their three children. She added that she would continue her own PhD studies through an online course. Education, she said, was her husband's passion.