A German man and woman have been arrested in Austria on charges of joining terrorists groups fighting in Syria where they had travelled with the woman's young son, officials said Thursday.

Police detained the 20-year-old German man of Turkish origin and a German-Iraqi woman, 33, on a train in Rosenbach in Austria on Saturday, police in southern Germany said.

Prosecutors in Munich in Bavaria had issued arrest warrants for the pair amid a police inquiry into the suspected preparing of a grave seditious act of violence, the city's police said in a statement.

The pair are alleged to have travelled to Syria in August "and joined there the armed fight by terrorist groupings", it said.Police in Germany have also arrested a man on charges of belonging to a foreign terror organization during an extended trip to Syria, officials said earlier on Thursday.

The 27-year-old German national, identified as Soufiane K., is alleged to have been a member of the Al-Qaeda-backed militant group Al-Nusra Front, the federal prosecutor general in Karlsruhe said.

He allegedly left his western German home in Ruesselsheim for Syria in July 2013 and later joined the group, a statement said.He is suspected of having received combat training and carried out guard duty for the militant group, among other things, it added.

The man returned to Germany in June, the federal prosecutor general said, adding that since then, suspicion of his involvement with Al-Nusra Front had grown leading to an arrest warrant.The suspect was due to appear before an investigating judge on Thursday.

An eight-year-old boy from Kosovo was reunited with his mother late on Wednesday after intelligence and security forces brought him back from Syria where he was taken by his “jihadi” father and kept for five months.

Concerns are mounting in Europe about the growing national security threat posed by jihadists returning from war-torn Syria and Iraq.An eight-year-old boy from Kosovo was reunited with his mother late on Wednesday after intelligence and security forces brought him back from Syria where he was taken by his “jihadi” father and kept for five months.

In US a North Carolina man faces up to 15 years in federal prison over plans to travel to either Syria or Yemen to join a terrorists group.Akba Jihad Jordan of Raleigh pleaded guilty Thursday in U.S. District Court to one count of conspiracy to provide material support to terrorists.

Federal prosecutors allege the 22-year-old Jordan and his 21-year-old co-defendant Avin Marsalis Brown spoke repeatedly with an FBI informant about their desire to travel overseas to fight with extremist groups that included al-Qaeda in the Arabian Peninsula, the ISIS group and jabhat al-Nusrah.

The pair is also alleged to have discussed using weapons to fight non-Muslims in the United States. Investigators later recovered an AK-47 assault rifle and ammunition from Jordan's apartment. Brown pleaded guilty in August and awaits sentencing.

U.S. government agencies are investigating on an American known as Abu Muhammad al-Amriki (R) who fighting with the ISIS militant group killed recently in the besieged Syrian border town of Kobani.

U.S. government agencies are investigating on an American known as Abu Muhammad al-Amriki who fighting with the ISIS militant group killed recently in the besieged Syrian border town of Kobani.

U.S. officials say at least a handful of Americans -including a Michigan woman and men from Florida and Minnesota - have died in Syrian fighting over the last two years.

In Asia Malaysia's defence minister has labelled efforts by a US-led coalition to push back the Islamic State group in Iraq and Syria "ineffective", and called for regional cooperation to prevent jihadists gaining a foothold in Southeast Asia.

U.S. Secretary of Defense Chuck Hagel (L) listens to Malaysian Defence Minister Hishammuddin Hussein (R) during a welcome reception for Southeast Asian defense ministers April 1, 2014 in Honolulu, Hawaii.

"Air strikes by the United States and its allies (against IS in Syria and Iraq) appear to be ineffective for now. So, we need to consider our own approach," Hishammuddin Hussein was quoted as saying in The Star newspaper.

Citing neighbours Indonesia the world's most populous Muslim nation the hilippines and Brunei, Hishammuddin said the region needed more intelligence-sharing and other cooperation on the IS threat.

Hishammuddin also lamented hesitation in the Arab world in condemning the group."The silence from Arab states is quite deafening when it comes to the IS issue," he said.

Concern is growing in Southeast Asia over the potential for the Islamic State to gain followers in the region.

Authorities in Malaysia, which has traditionally practiced a moderate brand of Islam, said they arrested 14 people this week, including a government engineer, for suspected links to the extremist group.

Those arrested included IS supporters who sought to recruit Malaysians and to arrange for their travel to Syria, according to police.

All told, Malaysian authorities say around three dozen have been detained this year for having IS-related activities. At least 40 Malaysians are believed to have left for Syria.