Last night the home of Iranian opposition leader Mehdi Karroubi was targeted with sound grenades, Saham News reports.

“Last night, intelligence forces cleared and blocked the alley and prepared the scene for thugs and hoodlums to attack the house,” says the report on Saham News. “They broke the building’s windows and threw three sound grenades inside the building.”

According to the report, Karroubi has told the security personnel who keep him prisoner, he will resist their pressures “to the last drop of my blood.”

Karroubi and his wife are under a strict house arrest that began before the mass protests of February 14. The revival of street protests last Monday prompted the Islamic Republic government to tighten security around the opposition leaders, and the judiciary says they will be prevented from issuing any further announcements.

While conservative factions have called for the opposition leaders’ arrest and execution, the establishment has announced it intends to keep them under strict house arrest instead.