The death toll from a boat collision on the Nile north of Cairo has climbed to 21, including women and children, a security source told Al-Ahram Arabic news website.
The health ministry puts the official death toll so far at 16, with four injured, state news agency MENA reported.
Preliminary investigations have shown that the boat had around 35 passengers on board when it was hit by the cargo ship, according to provincial prosecutor Attiya Negm Al-Din.
Health ministry spokesman Hossam Abdel-Ghaffar reported that at least seven children, ages ranging from two to 11, were among those who drowned.
According to the ministry of interior, the accident took place late Wednesday when a passenger boat traveling down the Nile near Al-Warraq collided with a barge, causing the boat to smash and capsize.
The skipper of the barge has been arrested. He will be detained for four days pending investigations into the incident.
One of the survivors, who refused to mention his name, said he was among dozens who were in the boat for a pleasure ride.
He said he jumped into the water alongside a friend and swam to a small boat after the collision.
Police have stepped up their presence at the scene of the accident where locals angered by the deaths blocked roads and shouted anti-government slogans.
The accident is the latest in many that occur on the Nile and off the Egyptian coast every year, usually blamed on rickety boats or loose enforcement of the law.
Last year, six people including a child, were killed when their chartered boat collided with a bridge near downtown Cairo.
In the deadliest such accident, a ferry sank in the Red Sea in February 2006, killing more than 1,000 people.