Ministers from 80 countries and nearly 500 experts gather in Paris from Wednesday for a conference on combating the financing of terror groups such as Islamic State and al-Qaeda, French officials said.

After two years during which Paris was scarred by terror attacks, tourists returned to the French capital in record numbers in 2017, hotel booking figures showed on Thursday.

As the dust settled over five days of angst in Spain after deadly terror attacks, the four remaining alleged members of a terror cell that carried out the carnage arrived in a Madrid court on Tuesday for questioning.

Spanish police said on Sunday they had uncovered a cache of 120 gas canisters at a house believed to be the bomb-making factory of suspects in terror attacks that claimed 14 lives, as Barcelona mourned victims of the rampage.

Police on Tuesday questioned a man suspected of deliberately mowing down Muslims in London, as the interior minister said Britain was ‘bruised but not broken’ by a series of terror attacks.

The suicide bomber who killed 22 people including children in Manchester likely did not act alone, Britain's interior minister said on Wednesday as soldiers were being deployed to key sites to help prevent further attacks.

Singapore has detained eight Bangladeshi men planning to stage terror attacks in their home country, the city state said, the second group of Bangladeshis investigated in the past six months.

The departure hall at Brussels airport, hit in March by a deadly double suicide bombing claimed by the Islamic State group, will partly reopen on Sunday, the management said.

Cutting edge gadgets are on show at Security and Counter Terror Expo, where transport security provided a key focus following the terror attacks in Brussels last month.

Indian Prime Minister Narendra Modi said his country shared Belgium's pain over the Brussels attacks as he added a wreath of white flowers to a sea of tributes outside Maalbeek metro station.

Airplane hijackings such as the one that unfolded on Tuesday involving an Egyptian airliner have become relatively rare since the September 11, 2001 terror attacks led to increased security.