The United States has stepped up weapons deliveries in support of a Saudi-led coalition resisting the advance of Shiite rebels in Yemen, a senior U.S. official said Tuesday.

"Saudi Arabia is sending a strong message to the Huthis and their allies that they cannot overrun Yemen by force," Deputy Secretary of State Antony Blinken told reporters in the Saudi capital.

Turkey and Iran agree on the need for a political solution to end Yemen's war, which has raised tensions between them, Iran's president said Tuesday after talks with his visiting Turkish counterpart.

"We talked about Iraq, Syria, Palestine... We had a long discussion about Yemen. We both think war and bloodshed must stop in this area immediately and a complete ceasefire must be established and the strikes must stop" in Yemen, Iran's President Hassan Rouhani said during a joint press conference broadcast by state television.

British police said Tuesday they were investigating a report that two teenagers, who come from the same town as one of the 2005 London suicide bombers, may have joined Islamic State jihadists in Syria.

The two 17-year-olds from Dewsbury in northern England are believed to have boarded a flight from Manchester to Dalaman in southwest Turkey on March 31, the regional police force said in a statement.

The bodies of two Spanish cavers were transferred to a morgue Tuesday as a fellow climber who survived their plunge into a deep ravine in Morocco's High Atlas mountains flew home.

An AFP photographer said Spanish diplomats were present as the bodies of Gustavo Virues and Jose Antonio Martinez arrived at the morgue of Bugafer hospital in the southern city of Ouarzazate.

Libya's internationally recognized parliament said Tuesday it has uncovered "new elements" behind the 2012 assassination of the U.S. ambassador when the American consulate was stormed in eastern city Benghazi.

"I have been tasked today with leading a team of inquiry," Tareq Saqar al-Jeruchi, deputy head of the parliament's security and defense committee, told AFP.

Four Tunisian soldiers were killed and six wounded Tuesday in an ambush in the Kasserine region where the military is battling jihadists, state television reported.

"Four soldiers have died as martyrs and six were wounded in an ambush against a military patrol," the Wataniya 1 channel reported, quoting the defense ministry.

Iraq has exhumed the remains of 47 people believed to have been massacred by jihadists from mass graves in Tikrit, the human rights ministry's spokesman said Tuesday.

"The number of remains that were exhumed so far is 47, and they were found in 11 mass graves," Kamel Amin told AFP, adding that the number is expected to rise.

Syrian authorities on Tuesday arrested a member of the domestic "tolerated" opposition as he returned to the country from a rights meeting in Geneva, a monitor and an activist said.

"The opposition figure and human rights activist Saleh al-Nabwani was arrested on Tuesday on the Lebanese-Syrian border," said Rami Abdel Rahman, director of the Syrian Observatory for Human Rights.

An initial ICRC flight transporting medical personnel has reached the Yemeni capital Sanaa, the organization said Tuesday, as fighting in the Arabian Peninsula country led to warnings of a humanitarian crisis.

"First @ICRC flight reached Sanaa. More to come by air and sea when clearances received to bring urgently needed medical supplies," Dominik Stillhart, director of operations at the International Committee of the Red Cross, posted on his Twitter account.

The Red Cross warned Tuesday of a "catastrophic" situation in Yemen's main southern city Aden, as loyalist forces battled rebels in the streets backed by shelling by Saudi-led warships.

The Iran-backed Huthi Shiite rebels and their allies made a new push on a port in the central Mualla district of the city but were forced back by militia loyal to fugitive President Abedrabbo Mansour Hadi, witnesses said.