Brussels extends terror alert as US issues travel warning

Brussels: Brussels will stay at the highest security threat level for another week over fears of an imminent terror attack, the Belgian government said, as the United States issued a worldwide travel alert for its citizens.

Authorities in Belgium and France were hunting for Belgian-born Salah Abdeslam, a key suspect in the Paris attacks on November 13, when gunmen and suicide bombers killed at least 130 people.

French police were on Tuesday analysing a suspected suicide belt similar to those used in the Paris assault, according to sources close to the investigation.

Authorities found the object -- which lacked a detonator -- in a dustbin in the southern suburb of Montrouge. Telephone data placed Abdeslam in the area on the night of November 13.

Another police source said the belt appeared to have "the same configuration" as those used by the militants.

Fearing a similar attack, Belgium maintained an unprecedented security lockdown in Europe´s capital Brussels, with Prime Minister Charles Michel warning Monday that the threat "remains serious and imminent".

Belgian authorities have charged a fourth person in connection with the bloodshed in Paris, which was claimed by the Islamic State group also known as Daesh.

Washington and Paris have stepped up their fight against Daesh, with France launching its first strikes from a newly deployed aircraft carrier in the Mediterranean and the United States calling for more international cooperation against the group.

Underlining heightened global fears of attacks after militants killed scores in Mali, Turkey, Lebanon and Nigeria in recent weeks, the US government issued a worldwide travel alert warning American citizens of "increased terrorist threats".

"Current information suggests that ISIL (another acronym for Islamic State), Al-Qaeda, Boko Haram and other terrorist groups continue to plan terrorist attacks in multiple regions," said a State Department travel advisory.

US President Barack Obama was due to meet French leader Francois Hollande in Washington on Tuesday.

The French president will also hold talks with Germany´s Angela Merkel on Wednesday, Russia´s Vladimir Putin on Thursday and Chinese President Xi Jinping on Sunday, as world leaders rally support for a global fight to crush Daesh.

The UN Security Council on Friday authorised "all necessary measures" to fight the group.