An Israeli man was arrested by police on the eve of Barack Obama’s visit on Tuesday for threatening to kill the president.

Channel 10 news said the man, a 63-year-old from Afula in northern Israel, was apparently mentally unstable. He was being investigated Tuesday night, the report said. He issued the threat over the internet, later reports said.

Later Tuesday, two right-wing activists, Raphael Morris and Henmael Dorfman, were briefly detained by police and released on condition they stay away from the Obama delegation. Police said they were questioned over past disturbances and in connection with the Obama visit. They said they opposed Obama’s visit, for fear it would advance moves toward Palestinian statehood, but had no intention of interfering in the visit, Israel radio reported.

The incidents occurred as Israel made final preparations to receive Obama, holding rehearsal ceremonies at Ben-Gurion Airport where the president is set to land early Wednesday afternoon. He will depart for Jordan on Friday afternoon.

The tarmac, on Monday, was jam-packed with American vehicles and helicopters that will service the president during his visit.

An airport official jokingly referred to the heavy US presence as a “friendly takeover” of the airport.

Some 3,000 police personnel will be deployed in Jerusalem on each day of the visit to ensure maximal security.

Outside President Shimon Peres’s residence on Tuesday evening, several hundred protesters gathered to urge Obama to release Jonathan Pollard, a spy-for-Israel serving a life term in solitary confinement. Obama said in an interview last week that he did not intend to free Pollard immediately, but would ensure rights available to all prisoners were made available to Pollard.

Pollard’s wife, Esther, was among the speakers at the Tuesday protest. Obama will hold two meetings at Peres’s residence, on Wednesday and Thursday, the latter of which will conclude with a state dinner in his honor.

Some 200,000 Israelis have signed a petition for Pollard’s release, which Peres is to hand to Obama.

During Obama’s visit the main highway from Jerusalem to Tel Aviv (Route 1) will be closed for lengthy periods of time. Also, the streets around the King David Hotel, where the president will be staying, will be closed for the duration of the visit.

The Israeli smartphone WAZE navigation app will be synchronized with Israel police, aiming to update drivers in real-time about blocked roads and to redirect traffic to alternative routes.