The Hamas government on Monday accused Israel of trying to assassinate Palestinian Authority Prime Minister Ismail Haniyeh with a poisonous substance sent to his office in Ramallah in an envelope. Seven employees working in the office were hospitalized after being exposed to the envelope, which carried a Tel Aviv postmark, said Deputy Prime Minister Nasser al-Shaer. The envelope was sent to Haniyeh's office in Ramallah although he is banned from leaving the Gaza Strip, where he has another office. Haniyeh claimed during a meeting of his cabinet in Gaza City that the envelope contained "poisonous gas" that was meant to kill him and other senior Hamas officials. "We have no doubt that the Israeli intelligence was involved in this criminal and dangerous act," he said. "This is not the first time that the government has received threats [from Israel]." Abdel Baset Matan, director of Haniyeh's office, said the envelope, which was addressed to Haniyeh, arrived in Ramallah in the morning by registered mail. He said that when he opened the envelope, he noticed that it contained a small yellow cloth. "I immediately summoned the chief of security in the office, Yacoub Fakih, who together with a number of workers opened the envelope," Matan recounted. "When they opened it, there was a strong smell in the room and all those present fainted." Fakih was said to be in moderate condition, while the remaining six employees were released hours later, a doctor at the Ramallah Hospital said. The doctor said he and his colleagues had not yet determined the nature of the substance and that the hospital together with the PA security forces were still examining the suspicious envelope. "It's too early to tell whether the envelope contained toxic material," he said. "We are trying to establish why some of the workers lost consciousness when they were exposed to the vent." Hospital director Dr. Husni Attari denied rumors in Ramallah that the envelope contained Anthrax. He said all the employees who were brought to the hospital suffered from breathing difficulties and stomach aches. "I can only say that they are all in good condition," he said. Following the incident, the office was evacuated and PA policemen began combing the building for suspicious objects. Ghazi Hamad, spokesman for the Hamas government, said he did not rule out the possibility that the envelope had been sent by the Israeli security forces. "It was sent from Tel Aviv and that's why we believe that this was an attempt to kill the prime minister," he said. Despite the allegations, sources in Ramallah did not rule out the possibility that the incident was in the context of the power struggle between Hamas and Fatah. "The Israelis aren't that stupid," said one source. "If Israel wanted to kill Haniyeh, they know that he is based in the Gaza Strip, not the West Bank."