"It is difficult to speak about the perpetrators' motives at the moment, but I cannot help feeling that this act might be directed against Croatia's policy of integration with the European Union," Prime Minister Sanader told reporters at the government headquarters.
He added that he was certain that this act would not jeopardise Croatia's path to the EU or the possible opening of membership talks.
"Regardless of who carried it out, this act does not promote our integration with the EU," Sanader said adding that his government would not tolerate such acts, regardless of the motives.
"There are people, both in and outside the country, who want to thwart Croatia's efforts to join the EU," the PM said, adding that by this he did not mean the legitimate Euro-scepticism which he said existed in every country, including EU member countries.
"We strongly condemn this crime and we will investigate it and punish the perpetrators," Sanader said when asked if the incident would jeopardise the start of membership talks with the EU and whether it could be linked with the publishing of documents about a witness to testify against al-Q'aida and events following the recent arrest of businessman Hrvoje Petrac.
He said that he talked to British Ambassador John Ramsden this morning and asked him to convey his sincere regret to Prime Minister Tony Blair, as well as his government's determination to investigate and punish the perpetrators.
Sanader expressed satisfaction with the government's good cooperation with the government of Great Britain as the country chairing the EU and thanked for Britain's support to Croatia's bid to start membership talks with the EU.
Sanader said that the incident had nothing to do with the threatening letters received this spring by some western European embassies in Zagreb.
Everything is under control and every case was dealt with as it should have been, Sanader told reporters.
Answering reporters' questions, the PM quoted security reports saying that "Croatia is not and will not be a target of terrorist attacks."
Noting that he was not advocating self-censorship, he called on the media not to blow incidents out of all proportion.