PRAGUE, Jan. 1 -- Palestinian ambassador to the Czech Republic Jamal Al Jamal was killed on Wednesday by an explosion caused by inexpert manipulation of a safe in the sitting room according to the investigation as yet, said Prague Police spokeswoman Andrea Zoulova.

She said it was not an act of terrorism, adding the investigation continues and the police still check several versions.

She said the safe was strongly damaged and the safety system of the safe may have exploded.

Czech Police President Martin Cervicek also ruled out the possibility of terror attack.

"I can say now there exists not a sole indication that would point to an act of terrorism or any other way of attacking the persons who were moving around the premises," said Cervicek on Czech public television.

"The units that cooperate in the anti-terrorism struggle and the like are now checking certain information," He said, adding bomb-disposal experts are still checking all spaces concerned, the investigation is only in its initial stage and that an expert opinion will still be needed.

He said that the Czech police will look into why explosives were on the premises of the future Palestinian embassy in Prague-Suchdol where they should not have been.

He would not say whether the police found other weapons or explosives in the buildings.

According to local media report, the blast could have been caused by an explosive system. The ambassador's wife and son escaped unscathed.

A 52-year-old woman was treated on the spot and then taken to the Prague-Motol Hospital on suspicion she inhaled by-product gases and over a stress reaction.

According to as yet unconfirmed information by Czech media, the explosion occurred when a safe placed in the house was opened.

Police evacuated 51 people in the vicinity of the Palestinian ambassador's residence to facilitate investigation, and they have returned home at present.

Czech Foreign Ministry spokeswoman Johana Grohova said that the ministry will not comment on the matter as long as the police investigation is underway.

"We express our sympathies on the ambassador having succumbed to the injuries," she said earlier in the day.

Chief surgeon Daniel Langer of the Central Military Hospital in Prague, where Jamal Al Jamal was treated, said that the ambassador suffered chest, stomach and head injuries.

The Palestinian ambassador officially assumed the post on Oct. 11, 2013. He moved to the residence where is to be a new seat of the Palestinian embassy a few days ago. The explosion did not cause damage outside of the house.