Palestinian security forces have arrested 20 Salafists in a series of raids across the West Bank, a security source said on Sunday, denying any of them had ties to Al-Qaeda.

"In the last few days, around 20 people were arrested in Nablus, Jenin and Qalqilya," the senior Palestinian security source told AFP on condition of anonymity, saying those detained "embrace the Salafi ideology but are not affiliated with Al-Qaeda."

His remarks were made a day after as a Gaza-based group affiliated with Al-Qaeda confirmed it was operating in the West Bank for the first time, saying three Palestinians killed by Israel near Hebron last week were its operatives.

"The global jihadi doctrine has reached the bank of pride, the West Bank," the group said in a statement released late on Saturday.

"Those brothers and that cell (..) are only the tip of the iceberg."

But the Ramallah-based official denied that militants with Al-Qaeda ties were working out of the West Bank, which is ruled by the Western-backed Palestinian Authority.

"There are no Al-Qaeda affiliated groups operating in the West Bank but there are a few Salafi Jihadi groups," the source said.

Those arrested were all former members of the Islamist Hamas movement which rules Gaza, he said, noting that they "embrace the global Muslim Brotherhood ideology that produces ideologically extreme groups."

"These men are connected locally through technology, but are unarmed," he said.

"They are not members of Al-Qaeda and they don't receive any instructions or weapons from it."