SINGAPORE, Jan 20 - Singapore, a wealthy multi-ethnic city state, arrested 27 Bangladeshi construction workers who supported Islamist groups including al Qaeda and Islamic State and deported 26 of them, the government said on Wednesday.

The 27 were arrested in November and December, the home ministry said. Twenty-six were deported, while the last one was jailed for attempting to leave Singapore illegally after hearing of the arrest of the others, the home ministry said.

The investigation revealed that several members of the group had considered carrying out armed violence overseas, but did not plan any attack in Singapore. Some of them had contemplated taking part in armed jihad in the Middle East, the ministry said.

"I appeal that we be more vigilant, whether against radical teachings and ideologies, or of any suspicious activities around us," Minister-in-Charge of Muslim Affairs Yaacob Ibrahim said on his Facebook page.

"At the same time, I hope we will remain united and not resort to discriminating (against) foreign workers here."

Singapore broke up plots for militant attacks after the Sept. 11, 2001, al Qaeda attacks on the United States. Recently, concern has been growing in countries around the world about individuals joining the cause of the Islamic State.

The Bangladeshis were encouraged to return home and wage armed jihad against the government in Dhaka, and tried to recruit other Bangladeshis to their group, the ministry said.

The announcement came a week after an attack by suicide bombers and gunmen in the heart of Jakarta, the capital of neighbouring Indonesia, highlighting the growing threat Southeast Asia faces from radicalised Muslims.