Egyptian authorities deported seven Palestinians to the Gaza Strip after they were detained for security reasons upon their arrival to Cairo airport, the state news agency said Saturday.
It was the latest indication of growing tension between the Palestinian militant movement Hamas in Gaza and Egyptian President Mohammad Morsi, who hails from the Islamist Muslim Brotherhood group from which Hamas is an offshoot.
The Palestinians were arrested in the same week that a state-owned Egyptian magazine published a report accusing Hamas of orchestrating the killing of 16 Egyptian soldiers in the Sinai Peninsula in August 2012 — one of the bloodiest attacks against the Egyptian army in decades.
Hamas officials deny involvement in the deadly attack and also say the seven Palestinians were wrongfully held.
Egypt's Muslim Brotherhood said in a statement that Hamas leader Khaled Mashaal assured the group's supreme guide, Mohamed Badie, that "Hamas and all the Palestinians respect Egypt's security and do not intervene in its internal affairs."
The two met at Badie's office in Cairo on Saturday.
Mashaal also told Badie that the Palestinians consider Egypt a "strong pillar of support for the Palestinian issue and appreciate the sacrifices of Egypt and the Egyptian army."
Hamas had poor relations with former longtime Egyptian ruler Hosni Mubarak, who cooperated with Israel in imposing a blockade on the Gaza Strip after the Islamist group seized control there following elections in 2005.
After Egypt's 2011 uprising that ousted Mubarak, the Muslim Brotherhood rose to power in Egypt, raising hopes in Gaza that Cairo's relationship with the enclave would improve.
The Palestinians, who were flying from Syria to Cairo, were detained on Tuesday because they did not have exit stamps, the state-run MENA agency reported. They were released three days later after investigations showed no illegal activity.
Syrian authorities do not stamp passports issued by the Palestinian Authority, which has a measure of limited self-rule over Palestinians in the West Bank and Gaza. Instead, they stamp papers that Palestinians hold as proof of entry and exits instead.
"Thank God for their safe arrival," leading Hamas official Mousa Abu Marzouk wrote on his Facebook page.
Cross-border tunnels are another issue that has raised tension between Egypt and Gaza.
For the past several weeks, Egyptian authorities have been destroying smuggling tunnels that crisscross the Egypt-Gaza border. Gaza smugglers use the tunnels to ship cheap fuel, scarce construction materials and commercial goods into the territory, which is largely under an Israeli-Egyptian blockade. Other tunnels are used to haul in weapons and sneak in militants.
The Egyptian effort appears to be aimed at closing down the illegal routes to better control what is going in, but Hamas has accused Egypt of destroying the tunnels in order to halt a thriving smuggling trade that has propped up the local economy for the past five years.
Egypt's military, in particular, appears to view Hamas with suspicion, in part because the smuggling network into Gaza appears to overlap with Islamist militant groups in the Sinai Peninsula. The defense minister recently warned that the military is prepared to confront "anyone who dares to harm Egypt's security or armed forces."