Up to 15 wanted Palestinian terrorists have returned to the Gaza Strip, security officials said Friday, complaining that the Palestinians have not fulfilled their obligations since taking control of their border with Egypt last week. The Palestinians responded that they had not violated a US-brokered deal for operating the Rafah terminal, and that the fugitives had the right to return. European monitors at Rafah said they are trying to settle the dispute to protect the border agreement, the biggest diplomatic achievement since Israel's unilateral pullout from Gaza in the summer. Palestinian security officials acknowledged that at least 10 wanted men have entered the coastal area, but said anyone with a Palestinian identity card can enter. Israel's demand that such fugitives be kept out are not part of the accord, the officials said. One of those to enter Gaza this week was Fadel Zahar, a Hamas activist and brother of Hamas leader Mahmoud Zahar. Fadel Zahar said he was exercising his right to return after spending years in exile in Lebanon, Sudan and Syria. "I am a resident of Gaza. My family lives here. I spent all my life here, but I was deported for political reasons in 1991," he said in a telephone interview. "I am a member of Hamas, I am not a leader of Hamas, I am proud of this membership." Even though Israel has no formal veto, the parties to the border agreement are now drawing up a list of people who will not be allowed to enter the Gaza Strip, said Julio De La Guardia, a spokesman for the European contingent. "There are some people who shouldn't be allowed to cross," he said, adding that the entry of fugitives was a cause for concern, but not a violation of the agreement. Palestinian Planning Minister Ghassan Khatib said that Israel and the US could propose names of those who should be banned, but that the Palestinians have the final say. Earlier this week, Prime Minister Ariel Sharon warned that if controls at Rafah weren't tightened, Israel would turn its crossings with Gaza into international border passages, a move that would sever a customs union with the Palestinian areas and cost the Palestinians millions of dollars. On Wednesday, Defense Minister Shaul Mofaz said during a visit to the Kerem Shalom terminal crossing that Israel cannot accept a situation whereby "complete, accurate and real time information" of Palestinians traveling between Egypt and the Gaza Strip is withheld. "The agreement stipulates very clearly that the Palestinian Authority is obliged to supply Israel with accurate real time information regarding the identities of those passing through the terminal," a security official told The Jerusalem Post. "However instead, they give lists of identity numbers without names, usually five to eight minutes late, making it almost impossible to decipher identities and whether they are barred from traveling or not." According to the agreement, in the event Israel protests the entry of a particular person, the Palestinians are required to detain that person for six hours - a time bracket that will allow Israel and the PA to state their case before the European Monitoring team located at the terminal. "If the situation does not improve, and the Palestinians fail to cooperate, we will close the Erez and Karni crossings," Mofaz told reporters. "They will become international crossings in all senses and I hope the Palestinians understand the significance of such a step."