The flight data and cockpit voice recorders from Malaysia Airlines Flight 17 safely arrived at a UK laboratory on Wednesday morning and investigators have already begun to pore through their data.

So far, investigators say, so good.

Officials who examined the Cockpit Voice Recorder say it "was damaged but the memory module was intact."

They report seeing no evidence of manipulation, according to the Dutch. Its data, they say, was successfully downloaded and contains "valid data" from the flight's cockpit.

The flight's so-called "black boxes" were handed over to the Dutch Safety Board in Kiev Tuesday evening and promptly shipped by air to the United Kingdom. They are currently being analyzed by an international team of experts at the Air Accident Investigation Branch (AAIB) laboratory in Farnborough, England.

The Netherlands, which lost nearly 200 citizens on the flight, has taken over formal responsibility for the air crash investigation.

Investigators say the analysis of the two black boxes will take several weeks. On Thursday, the AAIB plans to examine the Flight Data Recorder, the second of the boxes. The data will then be combined.

The black boxes were seized last week by pro-Russian separatists before being given to representatives of the Malaysian government Monday.

The handover was negotiated by the Malaysian prime minister.

Officials hope the black boxes contain clues as to what downed the jetliner, killing 298 people on board. Some of their bodies arrived in the Netherlands on Wednesday as nearly 1,000 family members looked on.

U.S. intelligence officials believe Russian-backed separatists in eastern Ukraine likely shot down the plane with an SA-11 surface-to-air missile.

The most likely explanation for that, according to a senior official, is that the plane was shot down by mistake.

Still, the Obama administration has been pointing the finger at Russia for backing the separatists, who have been fighting with Ukrainian forces for months. On Monday, President Obama said Russia had gone beyond just arming the separatists — it had trained them to use the heavy-duty artillery.

"Russia has extraordinary influence over these separatists. No one denies that. Russia has urged them on. Russia has trained them," Obama said. "We know that Russia has armed them with military equipment and weapons, including anti-aircraft weapons. Key separatist leaders are Russian citizens."

"We don't know a name, we don't know a rank and we're not even 100% sure of a nationality," one official said — adding that "there is not going to be a Perry Mason moment here."

Amanda Wills and The Associated Press contributed to this report.