Fatah gunmen have threatened to storm the Jordanian embassy in Gaza City to demand the release of one of their friends who was arrested by the Jordanian security forces upon his arrival in Amman last week. Following the threats, Palestinian Authority security forces beefed up their presence around the Jordanian embassy and ambassador's residence in Gaza City. Imad al-Assi, a senior member of the Aksa Martyrs Brigades, from Rafah, was arrested at Amman airport shortly after he flew in from Egypt. The Jordanian authorities initially denied that he was being held, but later confirmed he was in custody. No reason was given for the arrest. Assi's friends said he traveled to Jordan for treatment from wounds he had sustained during the intifada. "We urge the Jordanian authorities to release Assi immediately," said Abu Thaer, a spokesman for the Fatah gunmen in the southern Gaza Strip. "We respect the Hashemite Kingdom and the excellent relation between the Palestinians and the Jordanians." Another spokesman, Abu Qusai said the Jordanian authorities have refused to give any reason for the arrest of the top Fatah militiaman. "They haven't been very cooperative," he said. "In the beginning, they even denied that Assi was being held in Jordan. Later, when a Jordanian parliamentarian interfered, the [Jordanian] security forces admitted that they were holding him." The two Fatah representatives said their group was in touch with the PA leadership in a bid to secure the release of Assi. They also denied that the Aksa Martyrs Brigades were planning to target the Jordanian embassy or Jordanian diplomats in the Gaza Strip. Assi, 43, was one of the Fatah candidates who ran in last January's parliamentary election. PA security officials said that the Jordanian ambassador, Yehya al-Karaleh, had promised to raise the issue with the Jordanian authorities. The officials added that some Fatah gunmen had threatened to raid the Jordanian embassy of kidnap a Jordanian diplomat in protest against the arrest. "We are taking these threats very seriously," said one official. "That's why we have taken strict security measures to ensure the safety of all Jordanian diplomats here."