Suicide bombers struck the Iran Embassy on Tuesday, killing 23 people, including a diplomat, and wounding more than 140 others in a “message of blood and death” to Tehran and Hezbollah — both supporters of Syrian President Bashar Assad.

The double bombing in a Shiite district of Beirut pulled Lebanon further into a conflict that has torn apart the deeply divided country, and came as Assad’s troops, aided by Hezbollah militants, captured from rebels a key town near the Lebanese border.

The bombing was one of the deadliest in a series of attacks targeting Hezbollah and Shiite strongholds in Lebanon in recent months.

An al-Qaida-linked group said it carried out the attack as payback for Hezbollah’s backing of Assad forces against the mainly Sunni rebels as the Syrian civil war increasingly becomes a confrontation between regional powers.

The Syrian army’s border offensive is part of a larger government push that started last month and has seen forces loyal to Assad firmly seizing the momentum in the war, taking one rebel stronghold after another.

The attacks raised fears in Lebanon that Islamic extremists, now on the defensive in Syria, would increasingly hit back in Lebanon. The country is suffering the effects of competing sectarian loyalties.

“People fight outside (Lebanon), but send their messages through Lebanon. With bombs,” said a mechanic whose store windows were shattered by the blasts.

The midmorning explosions hit the neighborhood of Janah, a Hezbollah stronghold and home to several embassies and upscale apartments, leaving bodies and pools of blood on the glass-strewn street amid burning cars.

U.N. Secretary-General Ban Ki-moon condemned the attacks and called on all Lebanese to recognize that “such appalling and indiscriminate acts of violence” target everyone in the country, U.N. acting deputy spokesman Farhan Haq said.

U.S. Secretary of State John Kerry called the bombings “senseless and despicable,” and said “our hearts go out to the Iranian people after this violent and unjustifiable attack claimed the life of at least one of their diplomats.

The dead Iranian was identified as Ibrahim Ansari, a 54-year-old diplomat who took up his post a month ago and was overseeing regional cultural activities, said Iranian Ambassador Ghazanfar Roknabadi, speaking to Hezbollah’s Al-Manar TV from inside the embassy compound.

Also among the dead was Radwan Fares, a Lebanese national who headed the facility’s security, according to a Lebanese official at the embassy.

The first suicide attacker was on a motorcycle with 4.4 pounds of explosives and blew himself up at the embassy’s main gate, damaging the three-story facility, another Lebanese security official said.

Less than two minutes later, a second suicide attacker driving a car rigged with 110 pounds of explosives struck about 10 yards away, the official added.

Senior Hezbollah official Mahmoud Komati said at the scene that the attacks were a direct result of the “successive defeats suffered by (extremists) in Syria.”

He described the blasts as a “message of blood and death” to Iran and Hezbollah for standing by Syria, vowing they would not alter their position.

Shiite Iran is the main Mideast backer of Assad’s government, believed to be providing it with key financing and weapons.

A Lebanese al-Qaida-linked group, the Abdullah Azzam Brigades, claimed responsibility for the attacks, saying they would continue until Hezbollah withdraws its forces from Syria.