Several hundred people chanted "We want justice" and demanded that authorities catch whoever was responsible for downing Flight 17 in rebel-held eastern Ukraine, killing all 298 people onboard.

Western countries have accused the pro-Russia separatists, possibly with help from Moscow, of shooting down the plane. The United Nations Security Council unanimously backed an Australian-drafted resolution Monday demanding that the rebels controlling the crash site refrain from compromising evidence.

Tuesday's rally was organized by the youth wing of the United Malays National Organization, Malaysia's largest political party.

A Russian Embassy official said that staff members had been ordered to stay inside the embassy compound. She did not want to give her name as she was not authorized to speak to the media.

One of the demonstrators, Chris Wong, said the protesters were "not accusing anyone" for last week's disaster.

"We want to ask Russia and also Ukraine to cooperate with investigations," he said outside the Russian Embassy.

Russia's ambassador to Malaysia, Lyudmila Vorobyeva, reiterated earlier Tuesday that Russia had nothing to do with the plane crash and pointed the finger at Ukraine.

"The rebels do not possess any defense systems that are capable of shooting a plane at the altitude of 10,000 meters (32,800 feet). They do not have this kind of system. Russia never supplies this kind of system," she told a news conference.

Vorobyeva said that Russia was not "playing" games of laying blame without any evidence. "We are not doing that. We are calling for a thorough investigation that could produce evidence of who is responsible for this tragedy," she said.

Some protesters handed a letter to the United Nations office in Kuala Lumpur earlier in the day, asking for the U.N.'s support in helping ensure that the investigation into last Thursday's crash is not hampered.

Early Tuesday, the rebels handed over both black boxes from Flight 17 to Malaysian investigators in the Ukrainian city of Donetsk. Malaysian Prime Minister Najib Razak said the handover was part of an agreement he had reached Monday with rebel leader Alexander Borodai.

Najib said the black boxes appeared "to be in good condition" and that they would be "held securely in Malaysian custody while the international investigation team is being formalized."

"At that time, we will pass the black boxes to the international investigation team for further analysis," Najib said in a statement.

Meanwhile, family members of Malaysians who were aboard Flight 17 gave blood samples Tuesday to government health officials and police forensic experts. The samples are expected to be sent to Amsterdam to help experts identify the remains and bodies of the victims. There were 43 Malaysians aboard the plane.