Medics said they evacuated a 25-year-old male to hospital with "stab wounds to his upper body", with the suspected assailant suffering a head wound...
Police spokesman Micky Rosenfeld said the guard being treated was in serious condition, while the assailant had been arrested following the attack at the Jerusalem central bus station.
In a post on Twitter, Rosenfeld described it as a "terrorist attack".
Medics said they evacuated a 25-year-old male to hospital with "stab wounds to his upper body", with the suspected assailant suffering a head wound, his condition unclear.
The assailant was identified by police as a 24-year-old Palestinian from the occupied West Bank.
The attack comes as new protests flared in the Middle East and elsewhere over US President Donald Trump's recognition of Jerusalem as Israel's capital on Wednesday.
Two Palestinians in the Gaza Strip were killed in clashes on Friday and another two from Israeli air strikes in retaliation for rockets fired from the Palestinian enclave.
On Sunday, clashes broke out in Al-Arroub refugee camp in the south of the occupied West Bank, leaving one Palestinian wounded from rubber bullets, the Palestinian health ministry said.
Palestinian health officials say more than 1,100 people were wounded in Gaza, east Jerusalem and the West Bank from tear gas, rubber bullets, live fire and other means from Thursday to Saturday.