CAIRO, Oct 21 (Reuters) - Trucks with humanitarian aid that has been stranded in Egypt entered the Rafah border crossing with the besieged Gaza Strip on Saturday after days of diplomatic wrangling over conditions for delivering the relief.

Television images showed trucks moving into the border crossing area from the Egyptian side. Rafah is the main route in and out of the Gaza Strip that is not controlled by Israel, and the focus of efforts to deliver aid to Gaza's 2.3 million residents.

Israel imposed a total blockade and launched air strikes on Gaza in response to a deadly attack on Israeli soil by Palestinian group Hamas on Oct. 7.

Hamas, which has controlled Gaza since 2007, said a relief aid convoy of 20 trucks would enter on Saturday, carrying medicine, medical supplies and a limited amount of food and canned goods.

The U.N. has warned of "humanitarian catastrophe" in Gaza, where food has been running out and supplies of fuel needed to keep hospital back-up generators running have reached dangerously low levels.

U.N. Secretary-General Antonio Guterres visited the border on Friday in a push to get the aid in, saying a mechanism for inspection of the aid demanded by Israel was still being worked out.

Many of Gaza's residents have crammed into the south of the territory to avoid air strikes in the north.

Photo from Reuters