Surety, personal bond

Jarnail Singh, the Sikh journalist who made headlines in April last year for lobbing his shoe at Home Minister P Chidambaram, was on Wednesday assaulted outside a city court allegedly by supporters of Congress leader Sajjan Kumar. "I was pushed and manhandled while I was leaving the court," said Singh. Sajjan Kumar and nine others were granted bail in two cases related to their alleged involvement in the 1984 anti-Sikh riots. "The people who jostled me were supporters of Sajjan Kumar. One of them even threatened me with dire consequences," Singh added. Singh said he had gone to witness the court proceedings with Neerpreet Kaur, the Central Bureau of Investigation (CBI) witness in the case. "They (the assaulters) were trying to intimidate Nirpreet and other witnesses in the case also," he added. Police officers present inside the court complex intervened in the scuffle and Singh has filed a complaint at the Karkardooma court police post. The incident took place after the court granted bail to the 10 accused, including Sajjan Kumar. All of them furnished a surety and personal bond of Rs.50,000 each. The CBI had filed a chargesheet against Sajjan Kumar and the others in two cases for allegedly instigating mobs after the assassination of then prime minister Indira Gandhi Oct 31, 1984. Over 3,000 Sikhs across Delhi were killed in the carnage in the days following the assassination.

Could you please explain to me the emboldened parts?

Though I know "bond" means "a kind of investment", I cannot guess what "personal bond" means here.

Source : http://www.hindustantimes.com/News-Feed/india/Scribe-who-threw-shoe-at-PC-assaulted/Article1-517378.aspx