"We don't know when it will be possible to reopen the embassy," Tobias Nilsson said, refusing to say whether any direct threats had been issued against the mission. "We never comment on these kinds of security situations," he said.
The embassy said on its website on Thursday that "due to the security situation in Pakistan, the embassy of Sweden in Islamabad is closed until further notice". It did not provide further information.
Swedish interests have come under threat in Pakistan in the past. Two years ago, the Swedish embassy there tightened security after receiving threats following a suicide car bomb attack outside the embassy of its Scandinavian neighbour Denmark that left six people dead.
The Al-Qaeda terror network claimed responsibility for that attack, saying it came "in revenge" for Danish caricatures of the Prophet Muhammad.
Sweden has recently landed in the spotlight after the revelation of an international assassination plot against a Swedish artist who has also drawn ire for a drawing of the Muslim prophet with the body of a dog.
An Al-Qaeda front organisation had offered 100,000 dollars to anyone who murdered the artist, Lars Vilks, with an extra 50,000 if his throat was slit. Vilks has received numerous death threats and in the last two weeks alone, been attacked while giving a lecture at a Swedish university and had his house firebombed.