Yishai Shlissel spent 10 years in jail for his attack a decade ago when three marchers were wounded.

Prime Minister Benjamin Netanyahu condemned 'as a most serious incident' what was the worst attack in years on the event in Jerusalem, a city where the religious population is more prominent than in other parts of Israel. 

Marchers numbering about 5,000 and waving banners were heading down an avenue when an ultra-Orthodox man jumped into the crowd and plunged a knife into some of them, witnesses said. 

Police arrested Shlissel at the scene and were questioning him, police spokesman Assi Aharoni said.

It is understood that Schlissel was only released from prison three weeks ago following his 2005 attack which injured three people.  

Police and medics said the assailant had wounded six people. Two were taken to hospital in serious condition.

Jerusalem police confirmed the suspect had recently been released from prison after carrying out an almost-identical knife attack on the city's gay pride festival in 2005.  

'I saw an ultra-Orthodox youth stabbing everyone in his way,' said Shai Aviyor, a witness interviewed on Israel's Channel 2 television.

'We heard people screaming, everyone ran for cover, and there were bloodied people on the ground,' Aviyor said.

(dailymail.co.uk)