(Reuters) — A group of armed gunmen stormed the Tunisian consulate in the Libyan city of Benghazi on Monday to protest against an art exhibition in Tunisia which they said insulted Islam, a security guard who works inside the building said.

Kamal al-Gehani said the group of about 20 young men carrying Kalashnikovs forced their way into the building and burned the Tunisian flag inside.

“They knocked on our gates and pushed into the building. It was a holiday so no one was working inside except security,” he told Reuters.

Suleiman al-Gehani, an official with the foreign ministry who was called to help defuse the situation, said security officers had to negotiate with the group until they were convinced to leave.

“We had to convince them this wasn’t the civilized way to protest. They were very angry over the art work from Tunisia,” he said.

Thousands of hard-line Muslim Salafis rioted in Tunis this week to protest against the art exhibition which features a work that spells out the name of God using insects.

A Reuters reporter on the scene said there was a heavy police presence around the Tunisian consulate and that the roads leading to the building were blocked off by security cars.

Monday’s incident is the latest in a series of attacks on embassies and international buildings and convoys this year which have raised serious security concerns ahead of Libya’s first democratic elections slated for July 7.