Bangladesh's Army said on Thursday it had foiled a coup attempt by retired and serving officers last month that intelligence sources said was driven by a campaign to introduce sharia law throughout the majority Muslim country.
Army intelligence discovered that Major Ziaul Haque had fled the barracks and was contacting fellow officers and ex-officers through Facebook and by cellphone to encourage them to join the plot, Brigadier General Muhammad Masud Razzaq said.
"Specific information has been unearthed that some officers in military service have been involved in the conspiracy to topple the system of democratic governance," he told reporters.
He said around 16 former and active officers were involved. Some had been detained and would appear before a military court.
Impoverished Bangladesh has a history of coups, with army generals running the South Asian nation for 15 years until the end of 1990.
Prime Minister Sheikh Hasina took power in early 2009 and has since faced threats from Islamist and other radical groups.
A revolt in the country's paramilitary forces in February 2009 started in Dhaka and spread to a dozen other cities, killing more than 70 people, including 51 army officers. The revolt was quelled after two days but the country has since been shadowed by fears of further uprisings.
Sources in the army said the coup attempt was made late last month. "The attempt has been effectively controlled and now the process is on to punish the culprits," one military official said.
Intelligence sources said the coup attempt was fuelled by a retired officer and associates in active service who were campaigning to introduce sharia law.
Intelligence officers also said it appeared to have been planned over weeks or months by officers having close links with what they described as religious fanatics within and outside the military.
One source said the outlawed Islamist group Hizbut Tahrir had sent out a leaflet to troops saying "mid-level officers of Bangladesh army are bringing down changes soon".
Intelligence officials said hundreds of pro-Islamist officers and soldiers had been drafted into the army in recent years and many had now reached the middle ranks.
"A band of fanatic officers had been trying to oust the politically established government. Their attempt has been foiled," Razzaq said.
The attempted coup came at a time when the government began trial of Islamist leaders including former chief of the Jamaat-e-Islami party, Golam Azam.
Jammat, widely accused of opposing Bangladesh's 1971 independence from Pakistan and having committed war crimes, is the biggest religious party in the country and have thousands of militant followers, including in the defence forces, analysts say.
Syed Ashraful Islam, general secretary of Hasina's Awami League said late on Thursday that the government was "determined to crush any conspiracy against the country and the government, and that those found guilty would be brought to justice.
Addressing a rally outside Dhaka earlier this week, Hasina urged Bangladeshis to remain alert against attempts to thwart democracy in her country.
Hasina's father and Bangladesh's founding leader Sheikh Mujibur Rahman was killed along with most members of his family in a 1975 coup.
On Thursday, the prime minister said there had been nearly 20 abortive coups since then in which many army officers had been killed.
"Some vested quarters are trying to cause unrest in the country and in the disciplined forces in a bid to destabilise the government and disrupt democracy," she said without naming one individual or group.
Political analysts said Hasina was pointing the finger at her rivals, especially the leaders of the Bangladesh Nationalist Party, who are demanding the ousting of the government. She also warned those opposing war crimes trials, which she pledged to carry out in her 2008 election manifesto.
Retired Major-General Sayed Mohammad Ibrahim, a defense analyst, said the country and its democratic structures were reasonably immune to interference.
"Today's news about events in the army is worrying but will not cause any damage to democracy," he said.
(Additional reporting by Ruma Paul and Serajul Quadir; Editing by Nick Macfie and Alison Williams)