Palestinian fighter killed by Israel in targeted explosion, Lion's Den group says

A senior member of The Lion's Den was killed in an explosion in the occupied West Bank on Sunday, in what the newly formed Palestinian armed resistance group has called a targeted assassination by Israel.

Tamer Kilani was killed overnight in the Old City of Nablus when a bomb placed on a motorcycle parked nearby was detonated, The Lion's Den said in a statement.

The group said Israel assassinated Kilani, one of its "fiercest fighters", with a "sticky TNT device" and vowed to deal Israel "a harsh and painful response".

The Lion's Den has emerged in the Old City of Nablus in recent months, where clashes between Palestinian fighters and Israeli military forces have been occurring almost daily.

"The bomb exploded as he passed by and he became a martyr," Kilani's father, Sufian Kilani, who was not at the scene when the bomb went off, told Reuters. 

"We don't know whether the bomb was timed or triggered remotely."

Kilani had spent eight years in an Israeli prison on charges of belonging to the military wing of the Popular Front for the Liberation of Palestine, Palestinian media reported.

The Israeli military did not comment on its involvement in the killing, but an army spokeswoman claimed Kilani was involved in attacks targeting Israelis, according to AFP.

In one of two videos published by The Lion's Den on Telegram, an unidentified person can be seen parking the rigged motorcycle. The second footage shows the moment the blast occurred. 

Several Palestinian factions paid tribute to Kilani, with the Fatah movement describing his killing as a "cowardly assassination". A day of mourning has been declared in Nablus.

Dozens of Palestinian fighters and civilians have been killed this year amid an increase in Israeli military raids, most targeting the northern West Bank.