(VOVworld) - Indonesia's counter-terrorism forces have been on high alert after detecting several extremist elements from the Middle East popping up near Jakarta.

Indonesian anti-terror and bomb policemen check French Culture Institute (IFI Surabaya) as they heighten security at embassies and consulates across Indonesia, in Surabaya on November 16, 2015. (photo:news.asiaone.com)

Inspector-General Arief Dharmawan, deputy head of enforcement at Indonesia's National Counter-Terrorism Agency (BNPT), said South Tangerang and Cileduk have become new militant strongholds though militants are mostly lying low, but they are working and plotting. Besides raising security alert levels, Indonesia also tightened surveillance on citizens recently deported after trying to link up with the IS in Iraq and Syria via Turkey.

National police forces are intensifying security safeguards around embassies and consulates, particularly the French Embassy, French linguistic centers, and public places like shopping malls, theatres, or stadiums.

Sweden's security police raised their terrorist threat assessment to its highest ever level on Wednesday. The threat level was raised one notch to four, on a scale of five, meaning that there is a high probability that persons have the intent and ability to carry out an attack.

German Finance Minister Wolfgang Schäuble said army would be deployed in case of attacks.