Egyptian authorities have detained seven Palestinians who entered the Sinai desert through smuggling tunnels along Egypt's border with the southern Gaza Strip, officials said Friday. Security sources say the Palestinians were detained in a sting operation throughout the el-Arish area. The intruders, who were not identified, could not cross over the Rafah crossing due to unspecified complications on both sides, the officials said. The detainees were not suspected of security offenses. The seven arrests came after UN officials said Egypt appeared to have loosened monitoring of the border, citing recent economic figures that reflect a "booming" economy in the tunnel trade. The economy in the blockaded Gaza Strip is improving thanks to policy changes following the ouster of president Hosni Mubarak in February, according to the study, which was released Thursday. UNRWA, the Palestine refugees agency which authored the report, describes an upsurge in private employment, new imports and construction following the fall of the Mubarak regime. Although the unemployment rate remains high, construction jobs have grown by more than 9,400, increasing by 3.5 times compared to the first half of 2010, the report says. Gaza’s unemployment rate is still among the most severe in the world. A key factor, according to UN officials, is the inability of manufacturers to export their products to market. Israel controls all major crossings into and out of the coastal enclave. Although Egypt's Rafah crossing is primarily designed for pedestrians, even the passage of people remains restricted. Israel and Egypt began implementing a blockade in 2006 following parliamentary elections won by Hamas as well as the capture of an Israeli soldier in a cross-border raid into southern Israel. The siege has gradually been relaxed in recent years, but prohibitions on many imports and exports have decimated the Gaza economy and exasperated services for its aid-dependent refugee population.