DUBAI, United Arab Emirates, (AP) – Dubai authorities have arrested two suspects in last week’s slaying of a former Chechen rebel and the city’s police chief said Sunday that the Chechen president’s right-hand man masterminded the killing.

Sulim Yamadayev, a bitter adversary of Chechnya’s powerful Moscow-backed president, was shot March 28 outside a busy residential complex along Dubai’s shoreline.

Police Chief Lt. Gen. Dahi Khalfan Tamim said Chechen authorities have not cooperated with the investigation and that “Russia is also responsible for untying the knot of this crime.”

An Iranian and a Tajik who took part in the killing are in custody and four other suspects have fled to Russia, he said. None has been charged.

He told a news conference Sunday that one of those in custody said a Chechen member of Russia’s lower house of parliament who is close to the Chechen president planned the slaying. The parliamentarian, Adam Delimkhanov, is considered a close friend of Chechen leader Ramzan Kadyrov.

The suspect in custody said one of Delimkhanov’s guards provided him with the murder weapon.

“Our investigation found him (Delimkhanov) to be the mastermind of the assassination of Sulim Yamadayev,” Tamim said. The police chief said Dubai will seek Interpol’s help in arresting him and the four other suspects.

Yamadayev’s killing is the first politically motivated slaying in glitzy Dubai and the latest in a series of brazen assassinations targeting Chechen renegades in and outside of Russia.

“It’s very clear to us that the assassination of Sulim Yamadayev is a purely Chechen operation, which indicates settling scores in the UAE,” the police chief said.

It was not clear what Yamadayev was doing in Dubai, but the authorities said he arrived to the emirate four months ago on a Russian passport issued in the name of Sulaiman Madov.

Dubai police did not confirm the slain man was Yamadayev until days after the killing, suggesting that authorities were not aware a bitter opponent to the Kremlin-backed Chechen president had been living here.

In his homeland, he was a contentious figure. Once a rebel leader battling Russia, he later switched sides and led a battalion of former rebels alongside the pro-Russian government.

But he had long-running tensions with Chechnya’s current Kremlin-backed president, Kadyrov, which exploded in April. Kadyrov accused Yamadayev of involvement in abductions and murders, and an arrest warrant for him was issued.

Yamadayev and his family left Russia after his brother Ruslan was shot and killed during a busy afternoon rush hour in September just steps away from Russia’s main government building in Moscow.