The Palestinian ambassador to Prague was killed in an explosion that was triggered when he opened the door to a safe, Czech police said.
"According to information from the investigation so far, this was definitely not a terrorist attack," national police president Martin Cervicek said on Czech Television.
Police spokeswoman Andrea Zoulova said an explosive - which may have been part of a security mechanism - went off after the safe was opened. "With the greatest probability, an explosive device placed on the door of the safe was triggered," she said.
The Palestinian foreign ministry, in a statement reported by the official WAFA news agency, said the blast happened minutes after Jamal opened a safe that had come from the embassy's old offices.
Some safes can be fitted with small charges to destroy secret documents in the event of the lock being tampered with.
The Palestinian ambassador to the Czech Republic has died of his injuries after an explosion at his residence in Prague, Czech police have confirmed.
A Palestinian official has told Reuters that the Ambassador Jamal recently moved to the residence while another source said the blast was detonated when he opened an "old case".
Speaking from Ramallah, the source said: "He moved an old case with him to the new house from the old house. And when he opened it, the explosion happened."
The explosions took place at the two-storey residence of the Palestinian ambassador in the northern suburb of Suchdol.
According to local media reports, his family were in the building at the time but no-one else was injured in the blast.
The Czech Republic's public broadcaster has named the Palestinian Ambassador reportedly injured in an explosion in Prague as Jamal Muhammad Jamal.
Emergency services spokeswoman Jirina Ernestová is cited as saying that his injuries are "very serious" and that he is in a medically-induced coma in hospital.
Photographs from the scene showed a police cordon and a range of emergency service vehicles.
The Palestinian ambassador to the Czech Republic has been injured in an explosion at his residency in Prague, local Czech media are reporting.
The blast occurred before midday.
The level of the River Vltava has reached its peak and is expected to begin returning to normal levels, according experts cited in the Prague-based daily Mlada Fronta Dnes.
Some 60 roads remain closed as well as large parts of the city's metro system, the newspaper reports.
This was the scene in the early hours of this morning:
Flooding in the Czech capital Prague is expected to get worse before it gets better as water levels in the River Vltava reach their peak later this morning.
The Prague daily Lidove Noviny cited the Prime Minister Petr Necas as saying that water flow was expected to reach 3,300 cubic metres per second, up today from 2,900 last night.
The situation is made worse by the fact that the Orlik reservoir, which helps control the flow, is close to full capacity.
Temporary flood barriers and sandbags have been used to keep the water from Prague's Old Town - a World Heritage Site - after record floods in 2002 caused serious damage.
Czech Prime Minister Petr Necas pledged 300 million Czech crowns ($15 million) to relief efforts and said another 2,000 troops were ready to support the 300 soldiers already helping to erect temporary barriers and pile sandbags in Prague and other areas.
"The government approved the declaration of a state of emergency, which will enable a more effective rescue effort," said Necas after an emergency cabinet meeting, adding that there was another 1.3 billion crowns available to help fund the cleanup operation.
The historic area of Prague is a UNESCO heritage site boasting hundreds of well-preserved buildings, churches and monuments dating back centuries, including the Charles Bridge straddling the Vltava that was closed due to high water