Iranian authorities this week arrested Christian converts from Islam while they were meeting for worship at a home in the southern city of Shiraz, according to sources.

Officials are holding the Christians at an unknown location, they said.

The sources put the number of the arrested Christians, who belong to one of Iran’s many underground house churches, at between six and 10. Authorities often detain, question and apply pressure on converts from Islam, viewing them as elements of Western propaganda set against the Iranian regime; as a result, the converts are forced to worship in secret.

The identity of only one of those arrested on Wednesday (Feb. 8), Mojtaba Hosseini, was known. Authorities arrested Hosseini in 2008 along with eight other Christian converts on charges of being Christians, according to Mohabat News.

“I guess they have been watching Hosseini since then,” an Iranian Christian who requested anonymity told World Watch Monitor.

Shiraz is not a particularly “religious” part of predominantly Shiite Islamic Iran, the Christian explained, but persecution against Christians in Iran stems from the government more than from local religious sentiment. The families of the victims have requested information about their whereabouts, but authorities have refused to provide it, according to Mohabat News.

In past years authorities have arrested Christians around Christmas time, and the World Watch Monitor source said that the international community and media monitoring religious rights in Iran were expecting another crack-down last December. Instead, he said, the government was more cautious and arrested small groups over a wider period of time.

In December authorities arrested a group of Christian converts in the city of Ahwaz, about 874 kilometers (542 miles) southwest of Tehran in Khuzestan Province. Of those arrested, three Christians remain in prison: Pastor Farhad Sabokroh, Naser Zamen-Defzuli and Davoud Alijani. They are held in Ahwaz’s Karoun Prison, according to Mohabat News.

Sources have expressed concern for Sabokroh’s health. Prior to his arrest, which took place at his church’s Christmas service on Dec. 23, Sabokroh underwent cataract surgery. In prison he does not have access to the medication he needs for his eyes. His wife visited him briefly on Jan. 27 and said she was concerned about his health, as he has lost a lot of weight, according to Mohabat News.

Authorities had also arrested Sabokroh’s wife at the Christmas service and released her on Jan. 1 when she submitted the deed of a house as bail, according to Mohabat News. Christians are forced to put their homes up as bail in Iran, a practice that sources say is an extortion tactic to erode them of their finances and to better control them.

Authorities have not formally charged Sabokroh, Zamen-Defzuli and Alijani.

Noorollah Qabitizade, whom authorities arrested on Dec. 24, 2010, is also held at the Karoun prison in Ahwaz. Mohabat News reported that interrogators have put psychological pressure on Qabitizade in the last year and have forced him to sign statements in an effort to make him renounce his faith.

Farshid Fathi, who was arrested on Dec. 24, 2010 in Tehran, remains in the capital’s notorious Evin prison. Sources said a court hearing had been scheduled this month but were unable to provide more information.

Iranian authorities continue to arrest and subject Christians to harsh treatment, but many of these cases remain unknown to the outside world. At the end of January, Mohabat News released information on the case of Leila Mohammadi, whom authorities had arrested in July last year.

She spent 74 days in solitary confinement at Tehran’s Evin prison. On Jan. 18 a judge sentenced her to two years of prison for “collaborating with foreign-dependent groups, broad anti-Islamic propaganda, deceiving citizens by forming house churches, insulting sacred figures and acting against national security,” according to Mohabat News.

Authorities released her on bail on Dec. 28, 2011, and her attorney has sent her case to Tehran Province’s high court.

Iran applies sharia (Islamic law), which dictates that converts from Islam to other religions are “apostates” and thus punishable by death. Although judges rarely sentence Christians to death for leaving Islam, one Christian, Yousef (also spelled Youcef) Nadarkhani, is appealing such a decision in the northeastern city of Rasht.

Nadarkhani has been in prison since October 2009. A Rasht court found him guilty of leaving Islam and handed him the death sentence in September 2010.

Behnam Irani, who belongs to the same denomination as Nadarkhani, The Church of Iran, has been in prison in Karaj since May 2011; he turned himself in after authorities issued a warrant for his arrest, according to rights group Middle East Concern.

Irani was previously arrested in April 2010 and released on bail after a few months. In January 2011 a court found him guilty of “crimes against national security” and sentenced him to one year in prison. Authorities told him he must also serve a five-year sentence handed down in 2008.

Asked if there was a change in persecution trends from previous years, the World Watch Monitor source said, “Nothing has changed, the issue is the same,” explaining that the attitude of the government toward Christians remains hostile.

Authorities have prohibited musical worship and Bible distribution at the Central Church of Tehran, the largest and most visible Assemblies of God church in the country. Last December officials enforced a policy under which only invited guests could attend a Christmas service at the church, and in December 2009 the church succumbed to intense pressure by authorities to discontinue its Friday services, which had attracted the most converts to Christianity.