Woolwich, UK, Demonstration
Demonstrators protest the killing of British soldier Lee Rigby outside the Woolwich barracks in southeast London Sunday. Reuters

Authorities are investigating a pair of stabbings in a British prison and Paris train station that have been described as possible “copycat” attacks in the wake of the hacking murder of English soldier Drummer Lee Rigby in London’s Woolwich district, by suspected Islamist terrorists, last week.

Three prisoners at the Full Sutton prison in East Yorkshire reportedly took a warden hostage and stabbed him during a four-hour showdown with guards Sunday afternoon.

The warden was left with a fractured cheekbone, and a female prison guard who attempted to intervene also sustained an injury, according to the Telegraph.

The stabbing reportedly came shortly after an imam at Full Sutton asked inmates there to pray for Rigby, the 25-year-old soldier who was stabbed and hacked to death last Wednesday in broad daylight as he walked down a street near the Woolwich barracks in southeast London.

Investigators are reportedly treating the attack as a likely “copycat” stabbing “inspired” by the Woolwich murder, though the Ministry of Justice would neither confirm nor deny that the prisoners behind the stabbing were Muslim extremists.

“This had all the hallmarks of a preplanned attack inspired by the Woolwich atrocity. It’s something officials have been fearing could happen for years, and now it finally has,” a source told the Sun newspaper. “The officer was frankly lucky to survive. The attack was brutal.”

The UK “copycat” attack came one day after a man stabbed or slashed French soldier Cedric Cordiez, 23, in the neck with a box cutter in an underground Paris shopping center and transportation hub, according to the Independent.

The French government has not officially declared there to be a link between the Paris attack and the Woolwich murder.

But French investigators reportedly have a video showing the alleged attacker praying several minutes before the attack, which has contributed to authorities' belief that it was most likely a “copycat” incident based on the Rigby murder, according to Agence France-Presse.

French authorities have described the Paris attacker as being in his early thirties, muscular and appearing to be North African. Security cameras in the popular hub most likely captured the attack, investigators said.

Rigby was allegedly killed by Michael Adebolajo, 28, and Michael Adebowale, 22, two Muslim extremists who were shot after they attacked the soldier with meat cleavers and knives.

The site of Rigby’s killing has become a makeshift memorial for the soldier, with large numbers of mourners laying flowers and other items along the street in tribute.