Palestinian officials have apologized for an illegal weapons stash found earlier this month at the home of the Palestinian ambassador to the Czech Republic.

According to a statement issued Tuesday by the Czech foreign ministry, the Palestinians promised to prevent such occurrences in the future, the Associated Press reported.

Jamal Al-Jamal, who in October was named the Palestinian envoy to Prague, was killed January 1 when a safe in the home exploded. Conflicting reports said the safe had not been in use in 20 years or that it had been in regular use.

The safe had been moved recently from a former embassy building that had housed the offices of the Palestinian Liberation Organization more than two decades ago. The ambassador reportedly removed some of the safe’s contents before it exploded, according to AP.

After the explosion, a total of 12 illegal weapons were found at the Palestinian Embassy complex, Czech police said, including pistols and submachine guns, according to a Reuters report.

The discovery led to a deterioration in ties between the Palestinians and the Czech Republic.

A file photo of Palestinian ambassador to the Czech Republic Jamel Al-Jamal, who was killed in an explosion in his residence in Prague-Suchdol, Thursday, January 1, 2014 (photo credit: AP/CTK, Krumphanzl Michal)

A file photo of Palestinian ambassador to the Czech Republic Jamel Al-Jamal, who was killed in an explosion in his residence in Prague-Suchdol, Thursday, January 1, 2014 (photo credit: AP/CTK, Krumphanzl Michal)

After the incident, a senior Palestinian diplomat denied that the weapons, which were not registered with the Czech government, were illegal.

In an interview from Prague, the deputy Palestinian foreign minister, Taysir Jaradat, told the Voice of Palestine radio station that “these guns have been in the embassy for a long time — going back to the former regime of Czechoslovakia — and these guns were either licensed in the embassy or were given as gifts to the ambassador.”

“They are not in use,” he said.

During the Cold War, the Palestine Liberation Organization had strong ties with Eastern Bloc countries.

It remains unclear what caused the safe to explode, but the ambassador’s death is being investigated as a case of negligence.

JTA contributed to this report