Fifteen suspected leaders of radical Islamic groups have been charged with sedition in Bangladesh.
Hardline groups have been blamed for bombs over the past five years
Court officials said the men were accused of carrying out bomb attacks on rallies and buildings in attempts to destabilise the country.
The charges come amid a crackdown on militant Islamists which has included the banning of two groups.
Those charged include a professor who police say was named by some arrested militants as their spiritual leader.
Dr Muhammad Asadullah al-Ghalib, a professor of Arabic at Rajshahi University, was among the 15 defendants charged in a court in north-western Natore district.
If convicted they face possible life imprisonment.
Aid group attacks
Dr Ghalib openly heads a group called Ahle Hadith Andolon, which says its aim is to establish and popularise the teaching of the Prophet Mohammed.
But police say a number of arrested men who are suspected of belonging to the now-banned Jagrata Muslim Janata and Jamaat-ul-Mujahideen groups have said he is their spiritual head.
The court in Natore was told that the men were calling for an Islamic revolution to turn the country into a failed state and had become involved in activities against the interests of the state.
"They have been in a deep conspiracy against the state and have created an unstable situation by launching bomb attacks on cultural functions and aid agencies," investigating officer Farukh Ahmed told the court.
Two weeks ago, eight workers of two international development agencies, the Bangladesh Rural Advancement Committee and the Grameen Bank, were hurt in blasts.
No date was set for the next hearing, but Dr Ghalib has been brought to the capital, Dhaka, for further interrogation.
Police have previously failed to identify those responsible
The government, which has long denied the presence of Islamic militants in Bangladesh, launched the rare crackdown following strong criticism from the country's international partners.
More than 100 people have been killed in a number of blasts since 1999.
The government has so far failed to identify any of those responsible, although hardline Islamic groups were blamed in most of the cases.
According to police, more than 70 suspected militants have been arrested since the crackdown was launched last week
The Islami Oikya Jote, or Islamic Unity Front, which is a partner of the four-party ruling coalition, called the crackdown "a ploy to alienate the pro-Islamic forces from the government".
However the United States has welcomed the crackdown.
US State Department official, Christina Rocca, said the recent actions would contribute to the maintenance of law and order in Bangladesh.