A fire at the bottom of the flyover in the Bogside (Aoife Moore/PA)

Disorder yesterday flared in Londonderry for a sixth successive night.

Youths in the city's Bogside threw petrol bombs at police and random passing vehicles, and also lit a fire on a flyover.

The disturbances in the republican neighbourhood came after Derry hosted its first Twelfth parade in five years.

Yobs wearing hoods and masks, some of them very young, were among a crowd of around 200 that gathered as trouble erupted.

At one point a teenager hurled a petrol bomb at the windscreen of a passing van at point-blank range.

The majority of the petrol bombs were aimed at police stationed on the city walls overlooking the Bogside.

The PSNI said last night: "We regret to say that we are experiencing further disorder in the area of the Bogside with a number of petrol bombs already thrown at police.

"There is a large crowd gathering. It is clear that there are young children involved. Parents - make sure your children aren't involved."

On the Eleventh Night, 16 petrol bombs were thrown at police and two blast bomb-type devices were hurled up on to the walls, sparking a security alert around the Apprentice Boys Memorial Hall, the gathering point of yesterday's parade.

As ammunition technical officers examined the devices and the area was cordoned off, there were fears that the march would be disrupted.

However, the devices were made safe and taken away for further examination, and the police cordon was lifted just minutes before the first bands embarked on the parade.

Approximately 60 lodges representing the districts of City of Londonderry, Donegal, Coleraine, Limavady, Macosquin and Claudy participated in the main demonstration and were accompanied by more than 40 bands.

Tourists were among those who lined the parade route, seemingly undaunted by the large police presence.

Dixie Adams and her husband John from Hawaii said they found the march exciting.

"We are here at an interesting time," she said.

"We just love being here today. We had no idea what we were getting into.

"I'm glad the police are here. I feel very secure."

Her husband said it was sad that so many officers had to be there to facilitate the parade.

"It's unfortunate that there is a necessity for the police when it should be a day to watch the parade," he said.

"This is such a nice town and it's unfortunate that it has come to a level like this."

Barbara Wexler from New York said the heavy police presence didn't worry her.

"It's very interesting," she added.

"It's giving us a better understand of Irish history and it's all very complex and gives us a good handle of different countries and what their internal struggles are. We have that in the States also.

"The number of police here or the helicopter flying overhead doesn't faze me, I'm from New York."

Tensions were high on the return leg with crowds of nationalist protesters being pushed back by scores of PSNI officers from the parade route.

As the marchers passed by the Cenotaph in the Diamond the crowd exchanged insults with loyalist supporters on the opposite side of the road. One man was arrested.

Earlier, SDLP leader Colum Eastwood condemned the violence that has plagued the Bogside and Fountain interface in the run-up to yesterday's march.

"The continued disruption and attacks in Derry are absolutely reprehensible," he said.

"The people behind these attacks are morally bankrupt.

"It is high time that they were challenged, and it is time to deal with the underlying issues."

Belfast Telegraph