With the military’s ultimatum to President Mohammed Morsi set to expire Wednesday at 10am Eastern, tension continues to grow on the ground as each side ratchets up its threats. The Egyptian army says it’s ready to “sacrifice even our blood,” while Morsi vows defend his “constitutional legitimacy” with his life.

The death toll in overnight clashes rose to at least 23, according to the Associated Press.  The Independent reports that gun battles erupted during a large rally called by the Muslim Brotherhood at Cairo University. Hundreds of supporters and opponents of Morsi for hours battled with rocks, Molotov cocktails and ultimately gunfire.

Egypt Tension Rises: Army Says Ready to ‘Sacrifice Even Our Blood’ While Rebels Call for Morsi’s Arrest

Opponents of Egypt’s Islamist President Mohammed Morsi hold a large Egyptian national flag during a protest outside the presidential palace, in Cairo, Egypt, Tuesday, July 2, 2013 (Photo credit: AP/Hassan Ammar)

“At one point a pro-Morsi supporter strode down the main road next to the university, took aim with his shotgun and fired several rounds off down the street. Shortly afterwards the opposition attackers charged them back down the main avenue, sending rounds of birdshot ricocheting into the walls and bullets fizzing overhead,” the Independent writes.

A “Morsi Timer” clock counting down to the military ultimatum’s deadline was posted online by the Tamarod (rebel) movement which initially called for the massive June 30 protests against Morsi.

Al Arabiya reports that the Supreme Council of the Armed Forces (SCAF) wrote on its official Facebook page that the army is ready to sacrifice its blood to defend Egypt against “terrorists or fools.”

In a post titled “The Final hours,” the Egyptian military said, “We swear to God that we will sacrifice even our blood for Egypt and its people, to defend them against any terrorist, radical or fool.”

Al Arabiya points out that the statement was posted before Morsi’s televised address in which he rejected the Army’s ultimatum and said he would sacrifice his life to protect what he characterized as his legitimate rule decided upon in democratic elections.

The Egyptian Army says Morsi must reach an agreement with those opposing his rule by this afternoon or it will create its own roadmap and implement it.

While they first merely called for Morsi to step down, opposition leaders are now calling for him to be arrested.

In a statement, the Tamarod opposition movement said, “Not only are we calling for his departure but we call for him and his group to be sent for trial. We call on the Republican Guard to arrest Mohammed Morsi and send him for trial immediately.”

It is also calling for new anti-Morsi rallies: “The only response to Morsi’s speech is to protest on the streets in our millions, starting on Wednesday, so that he and his group hear the voice of the great Egyptian people.”

The leader of Egypt’s Coptic Christian community is also weighing in. The Coptic Orthodox Pope Tawadros II praised the anti-Morsi protests in a statement posted on Twitter.

“It is wonderful to see the Egyptian people taking back their stolen revolution in a peaceful way,” he said.

Not surprisingly, Hosni Mubarak who was ousted from power two years ago says the Islamist president should step down for the sake of the Egyptian people, according to Al Arabiya.