Iranian security forces arrested journalist and blogger Parastou Dokouhaki on January 16 at her home in Tehran, confiscated some of her personal belongings, including her computer, and sent her to Evin prison.
She was later charged with acting against Iran's national security, a charge that is routinely brought against political prisoners and prisoners of conscience in the Islamic republic.
Two days later, journalist Marzieh Rassouli, who writes about cultural issues, was arrested in the same fashion. Rassouli is also believed to be held at Tehran's Evin prison while facing the same charges as Dokouhaki.
January 18 brought more alarming news: the arrest of journalist Sahamedin Bourghani.
The three are among a dozen journalists, intellectuals, and activists who have been sent to prison in Iran in recent weeks.
The wave of arrests ahead of the March 2 parliamentary elections appears to signal attempts by the Iranian establishment to prevent any form of dissent.
The regime has also been tightening its grip on the Internet by putting new restrictions in place, in what seems to be an attempt to head off protests similar to those that shook the government two years ago.
'No Let-Up This Time'
The March parliamentary elections -- the first since the disputed 2009 presidential vote that led to mass street protests and threw the Iranian establishment into crisis -- are coming at a sensitive time.
Iran is under escalating international pressure and tough economic sanctions over its suspect nuclear program, making many Iranians unhappy.
The establishment in Tehran is also grappling with deep internal fissures and an ongoing power struggle between forces loyal to Supreme Leader Ayatollah Ali Khamenei and President Mahmud Ahmadinejad. The conflict looks set for a showdown during the elections.
The current crackdown goes against the trend of the past years, when Iranians were used to a loosening of political and social pressure ahead of elections. The tactic was used by the authorities to encourage voter participation in the upcoming polls.
The regime, which lost much of its legitimacy during the brutal crackdown on peaceful protesters in 2009, is now feeling very vulnerable to any kind of instability, and therefore is relying on force and suppression, says Washington-based Iran analyst Ali Afshari.
"The establishment wants to send a message and say that unlike previous elections, in the upcoming vote, the [political] atmosphere will not open up at all and it will not tolerate any unrest or any move that would go against the state's plans," Afshari says.
'No Reason Needed'
Reza Moini, a spokesman with the Paris-based media-rights watchdog Reporters Without Borders, tells RFE/RL's Radio Farda that the arrests are aimed at isolating Iranian society and creating fear among activists.
"Any type of activities that deals with informing others, can be one of the reason for the arrest -- in some cases [it appears] that there has been no reason for the arrest," Moini says.
Most of the recent arrests have targeted journalists and online activists and writers, including Simin Nematollahi, a contributor to a website that covers news about Sufis, and Mohammad Solimaniya, the head of a social-networking site.
National religious activists Saeed Madani and Ehsan Houshmand, are also among those who have been jailed in the past few weeks. Arash Sadeghi, a student activist who had been jailed in the postelection crackdown and later freed, was rearrested last week.
One Tehran-based observer who does not want to be named tells RFE/RL more arrests are expected as the election nears.
RFE/RL's Radio Farda broadcaster Hannah Kaviani contributed to this report