The Daily Politics

Agnes Poirier, a French journalist, says normally people in Paris would have taken to the streets to march, because "that's what we know". The people wanted to be there and to do something. However large gatherings have been banned in Paris so, she says people walked from one site to the other.

She says the French are in a situation where "compatriots are killing their compatriots" adding people have got used to the heavy security presence and being vigilant after the attacks in January on the offices of Charlie Hebdo. But she says it was the scale of the attack that was shocking.

Conservative backbench MP Liam Fox says the UK should be taking part in air strikes against Syria, alongside France. He says "if it is necessary the government should act and then explain its actions to parliament" later. Dr Fox adds "a weird constitutional convention" appears to have developed since the Iraq war that the government seeks the backing of MPs before taking military action despite their being no need for the government to seek the backing of MPs before taking such action.

More from the G20  Summit press conference. The Prime Minister says he told Mr Putin that bombing moderate opposition groups in Syria was "a mistake". 

He adds there are some signs that the Russians were focusing more on IS and he wanted to see that continue. Mr Cameron says that the gap between the UK and Russia has been reduced and there will have to be compromise on both sides over Syria.

Asked about UK involvement in bombing IS targets in Syria Mr Cameron admits he needs to "do more" to persuade people and take parliament with him.

David Cameron says intelligence on foreign fighters will be shared between countries to stop them from travelling.

He says agreement has been made to  strengthen global aviation, with the UK giving "technical and financial assistance" to vulnerable countries. He adds spending on aviation security will be doubled in this Parliament to tighten security worldwide.

He called the situation in Syria the "most urgent need of all" and says a political solution is needed. Mr Cameron says he urged Russian President Putin to help Syria transition away from "President Assad and his ruthless brutality".

Reuters now says Salah Abdelsalam has not, we repeat not, been arrested after all. 

Belgian public broadcaster RTBF said earlier that police had detained a person during a raid in the Brussels district of Molenbeek, but it is not as first thought Salah Abdeslam. 

Reuters is reporting Belgian broadcaster RTL as saying Brussels police have arrested Salah Abdeslam, the Frenchman wanted in connection with the Paris attacks, during an operation in the Belgian capital earlier. There has been no official announcement as yet .

Speaking at a news conference, the French Interior Minister, Bernard Cazeneuve, said France would "destroy" those who sought to attack it.

He says "the reply of the Republic will be solid and total. Those who want to hurt the Republic they will be attacked they will be dealt with and those who help them".

Theresa May will make a statement to MPs in the House of Commons on the Paris attacks at 15:30 today, the Home Office has confirmed. The Home Secretary will make the statement after Home Office questions at 14:30.